From my understanding the script is based on Perfect World 3 with elements of Continents+. I don't think I follow you; how would having a Pangaea option defeat the purpose of the script? The main draw for me is the terrain generation (which admittedly is already better in the vanilla Pangaea maps than Continents).
I seem to remember the original post mentioning that the map is supposed to equalize our playing experience so that it's easier for us to discuss balancing stuff. The mod already was balanced "the most" for Continents Plus, no?
Regarding Passages, I do see your point. I often play on smaller maps, may those be one reason for why there's less "ocean-all-around"? Kinda due to smaller 'margins of error'?
I was getting rather burned out trying to learn how Civ 5 manages rivers (it's a HUGE pain and designed very badly)... so I will probably focus on easier stuff for a while. I think sea level, rainfall, and world age options should be simple. I'll probably look into it tomorrow.
Just remember we are now talking not about the icing on the cake, but the cherry on top (or the other way around, whichever you prefer

). It's already a fantastic thing. If I understood you correctly, you want to look into the easier stuff tomorrow? That's probably the better thing. Some change is good and you've done lots with the map now.
EDIT: @jacktannery, You are right, there's an error in the lua file for me as well. There's a file and a runtime error, I'm not sure what that means or how to solve it right now...
EDIT2: You only should need to copy the map file to the maps folder if you want to play it in non-modded game. It should work as well if you activate the communitas map mod on its own. I looked into the modinfo-file and it seems it doesn't load the communitas.lua file (line 32 in .modinfo), but that doesn't solve the issue for me, I'm looking around a bit, but I really have no experience in modding...