That's sneaky. I like it !
When people point out bugs and issues, half of the time they're not using the up-to-date version. So I have to somehow prevent myself from wasting time on issues that are no longer there.

I'm not sure what I would think of people if I saw one - deliberately - buy a keyboard without numpad

.
I feel that's our age showing when I instinctively agree with you on that one - even if right afterwards I realize that it's been a while I pressed anything on my numpad...
There is only one recurring error left (which may be due to lack of capacity on my 'puter) and that is in connection with a peace treaty, where - sometimes - the game locks/ends because it can't figure out how to move ships out of a previously "hostile" area. But I have "learned" how to fix it via the WorldBuilder/diplomacy menu, so it isn't a serious problem.
I can't say for sure if that one was already fixed in the current version or not and unfortunately you can't even provide a test case, as there is no way I'd be able to run your saves on my side...
If I may, the phrase "Historia est vitae magistra" is not wrong but it sounds very bad to someone who has studied Latin. In that language the right words sequence should be "Historia vitae magistra est".
In all honesty, "est" is simply superfluous there, especially since it's not there in the original quote. But I agree, now that you point that out, if it is to stay, it should be at the end.
On that note, what about having each installer name the install folder accordingly, i.e. instead of just "Realism Invictus", have it be "Realism Invictus 3.7"? This would also help with the issue of supplying unpacked files to address the MAF errors without having to worry about leftover files in an installation when installing a later version. (As you pointed out being an issue in this thread:
https://forums.civfanatics.com/threads/memory-allocation-crashes.694013/) Being able to play without the memory limit putting a hard end on larger games would be a huge benefit to virtually the entire playerbase.
I'm not a big fan of messing with the installer script more than absolutely necessary to build a new installer (wasn't me who created it in the first place, and I usually just update the icons and version numbers), but when next the time is right for that, I'll see what I can do as the idea is reasonable.
I am not claiming that you are

But this mod has been a staple of Civ4 mods, and is consistently one of my top 2 mods that I recommend to people to check out (the other one being FfH2 + MNAI, something so entirely different you can't rank the two against another), so I think it's a big legacy to pass up on.
I am reasonably sure that the name change will not lead to the "loss of legacy". Searching for "Realism Invictus" will likely still lead people to the right place if I signpost everything correctly (explicitly mentioning the older name in the thread etc). Obviously, I am not dismissing your concerns as invalid, and it's something I also weighed in when considering, but I also feel it's the right time to do so. The new name may actually even create a splash of popularity, as it's likely that this will draw more attention than "a mod releases 3.7 version".
Now, the decentralization and reliance on the provinces most certainly became the ISSUE of the 3rd century crisis which would affect Rome's economic health long term. There were regions that did not recover from that by the time of the later German invasions. Ironically, it was Diocletian's bureaucratic reforms that the 3rd century crisis ended by doing away with what allowed Rome to conquer so much in the first place. He divided up the provinces into very small administrative centers and transformed the economy from "free market" to a command economy. In Civ IV terms, he switched civics. I say ironic, b/c the Empire became more centralized under Diocletian, these smaller adminstratice centers answered to the demands of Roman Emperor directly, no longer having governors get in the way. This would later prove to be doubly ironic as these smaller administrative centers would later lead to decentralization and to the foundations of feudalism which is decentralization to the max.
Never claimed otherwise - I mentioned the Third Century Crisis as a counterpoint to a rather ridiculous claim that Rome was somehow more immune to internal disorder than Han China. I am not sure there was no existential threat to the empire as an entity though, as it took two exceptional individuals (Aurelian + Diocletian) to end the Crisis.
To be fair, relying on foederati may be viewed as a form of extreme decentralization, but I think the greater issue was that foederati only became a handicap b/c elements of Roman leadership failed to assimilate the German refugees who for the most part wanted to be part of Rome.
I have a couple theories why this happened:
-Rome has been fighting the Germans for centuries, so I can see why the "Purists" (racists) wanted Rome to remain pure from German blood (nvm that Roman was a multiethnic empire). "Dirty barbarians, they have been our eternal enemies! Remember Teutoburg!"
-Rome always (as far as I know) assimilated people through conquests of territory. They never really had to assimilate tribes seeking refugee onto preexisting Roman territory.
-Good fashion palace intrigues. There was competition b/w "pure" Romans vs half Romans/half German elite. Nvm being a "pure" Roman is an oxymoron (multiethnic empire being pure is truly laughable).
-Rome for a time was an idea. Anyone could be a Roman. By the end, Romans gave up on the idea of Rome and replaced it with a narrow view of what it meant to be Roman. The price is indeed terrible when a country rejects its ideals and foundations
I feel that's an oversimplification / too modern take on things. The amount of bigotry towards "barbarians" was roughly constant throughout the entire Roman timeline, and that was one of the major drivers for the latinisation of the population - people in the provinces who wanted to advance in life had to take up Latin (or Greek in the East) cultural mannerisms. The problem with this approach, obviously, is that it cannot rapidly accommodate rapid change in social makeup. So it did indeed create a lot of internal tension with integrating a large number of new peoples, but even then, examples like Stilicho don't actually allow us to properly gauge how much of the rejection was driven by bigotry - and how much in his case by being objectively bad at what he did. If anything, his example is a hallmark of how high someone with Germanic origins could reach in the West despite their origins.
Fortunately, in the case of Rome, we have an almost ideal experimental setup with the Western and the Eastern halves. Both empires experienced a rapid influx of "barbarians" into their territories during the Migration Era (mostly Germanic in the West, mostly Slavic in the East), and we can see that given time and stability, the Eastern half has "digested" their influx, at least for the time being. As an aside for those who'd like to point out that the scale of influx was different, 8th-9th century Greece proper was largely Slavic by makeup:
Yet, with time, those Slavs that were in the territories under continuous ERE control (unlike the ones that were parts of the Bulgarian empire for a long while) were almost entirely assimilated over the next few centuries. Same would have happened - and was happening - with the Germanic tribes in the West, were the situation more stable. The empire was in such a decentralised state that the "fall of Rome" as we now see it in historiography wasn't really registered as such at the time. Some former provinces continued as before, considering the lack of Western Emperors as a purely temporary thing (the kingdom of Soissons being an extreme example that lasted until being absorbed by the Merovingians), and the "new management" in Rome - the Langobards - considered themselves a development of Roman administration, rather than a replacement thereof - which was true to a major extent, as the Lombard "invaders" took a mere century to harmonise with the local Roman population in terms of language, religion (while lots of them were Christians even at the time of the invasion, they were predominantly Arian - and shifted to Roman Christianity) and customs.
The "idea of Rome" was never gone; after a certain point, it just wasn't enough to keep the political entity going. What you're saying about "redefining" the cosmopolitan idea is much more appropriate to the Eastern Rome actually, as post-1204 reconstituted Byzantine Empire was progressively turning more and more into "kingdom of the Greeks" (owing to a large extent to losing most territories with non-Greek majority).
I firmly believe that the Germans were always going to be "the future" of the Roman lands when the Visigoths arrived. Rome had the choice to either accept that (assimilate the Germans) or reject it (keep them at arms length as foederati). Rome rejected destiny and destiny destroyed Rome.
-Why do I believe this? Simple fact that there were way too many German refugees coming in. They had strong demographics and a warrior culture. There was no exterminating them. Keep in mind, I am looking at the time period when the Visogoths first arrived or maybe shortly before that. This destiny was by no means set in stone but by the time the Visigoths came, this course was set.
-This is a cautionary tale to all nations who reject destiny.
As pointed out above, I feel there was no real "rejection" going on, at least not any more than in all the previous Roman history. Could Western Rome be preserved as a single political entity? Maybe. Would it have made any difference in the subsequent history? Probably not. "Rome" persisted as an idea anyway, well into the modern era. Had the Western Empire survived politically until, say, 9th century, I doubt it would have looked much different from the Carolingian Empire of the time.
Cue the Rome 1 Total War ost.
Oh that brings back memories. The OST was amazing...
But which version is the best (just in case).......
RTW1 with Europa Barbarorum. The one and only.