Have you tested the combat change? I think the way you have it will work fine, but I'm not an expert on how combat works (iCombatPercent is the only modifier that applies directly to the unit at all times - with everything else applying to the defender, I think the only interference will be from combat promotions, as the percents may add instead of multiply). For 3.0 I plan to clone bOnlyDefensive to the promotions.
I thought it would work too. But after a few tests it seems like it might not be working... the promotion is definitely giving minus 100% strength, but it doesn't seem to be stopping me from attacking and destroying a 1 strength shuttle with my 5-strength cloaked Prometheus (this was done in Millennium since my Star Trek mod has Wormholes installed and I haven't made the two modcomps compatible) with 99.99% odds. Which shouldn't be happening. But, same cloaked Prometheus (well, a different one, but I did the same thing) has 0.19% odds against a fellow Prometheus that I gave to the barbarians.
Not sure what is happening.
When the iCombat is a negative number, it works by the following equation, where to find the modified strenghth you: -100% = x/2, where x is the initial strenghth vaule. Consequently, -200% = x/4 and so forth. As you can see, no matter what you set this iCombat to, a unit will still be able to attack (in terms of being allowed, as their strenghth value will never be zero using this method. If you want a 'practical' zero a -10000% iCombat basically makes any unit useless in combat (Such a large number is need, due to the fact that a borg tataical cube 2, for instance, start with such a high strength value, that even with a -1000% iCombat modifier, it still will have a combat strenghth of 2.5.
In addition to this I have been observing the AI behavior with the 1.2 mod, and it does seem to be working (to some degree). I think the question we need to ask is, 'How best to set up cloaking, so that the AI can successfully use it, and to use it as an advantage, not a hinderance. Because I am no expert of how (or if even possible) to code the AI to use cloaking in even an elementary way (when compared to a cagey human) I think perhaps the following set up could be used.
1. Cloaking device should be given to units as a starting promotion only, according to cannon (And perhaps the cloaking tech could be used for the drill1, drill2 avalibility, and a new building that gives these{I have done this in may current game and seems to be working well, however, I was able to add only one promotion for this building "Espionage Centre-+2 espionage, +1 great spy points, 10% thwart spies, drill1 promotion for ships built, cost 120, availible with cloaking", does anyone know how to add two promotions with a building?}.
2. Allow all cloaked ships to fire while cloaked with a -25% to -75% (not sure needs to be balanced and tested) iCombat modifier. Yes I know this is not cannon, but I cannot see the poor AI being able to use it effectively otherwise. So, with the decloak in solar system setting, the AI get a ships that it can really use, full strenghth on the defence (in system) and a ship that can pick of weak or undefended units while skulking around. (Just as a side note, how can we get a cloked ship to be able to enter neutral territory without a DOW?)
3. As, TC01 suggested, moving the cloaking device to future tech worked well with the above mods.
Anyway, these are just my ideas, and in the games I played they seem to be working fairly well, thoughts?