Gauntlet, I'm very surprised that you did not touch a single thing in improvements and shipComponents. Are you happy with Stardock idea of balance?
Strictly speaking GRM was not intended to be a gameplay modification mod... it's delved into that... over time and as a result of my desire to flesh out the experience of using GRM. GRM is now in effect a visual "total conversion" and mostly a total conversion in terms of lore (I haven't modified everything yet, like the new artifacts).
I've generally endeavored to avoid changing the gameplay mechanics for three reasons.
1) This would only appeal to certain players and would decrease the audience of the mod. You'd be surprised how many people skip by my work because it's a "mod" where 90% of the thing if the shipsets. The only reason those are a "mod" is because StarDock's fleet editor is incomplete.
2) Because I wanted people to have an easier time making GRM compatible with most other mods. So as much as possible GRM is "append style".
3) Horemvore's amazing mod GST (and I'll never forgive him for choosing a similar acronym!) and before him Nasselus' [SP?] mods already modify gameplay enormously. GRM is pretty compatible with Horemvore's stuff and he has a much better understanding of the game's inner mechanics... I'd rather not compete lol.
4) Updating the mod is hard enough, if I also tried to update the game's rules and inner mechanics more, the work involved would detract from my ability to make ships and such.
5) Side note... the most difficult thing to mod in GC3 for me has been Mercenaries... they have like 5 files needing coordination and a lot of work, and the game is very fussy about whether the Merc ship designs must be in the game's directory or not, or in certain annoying zip files and such. Ideology was second place, just because of the sheer amount of text.
6) If SD were to create a "GC complete" version with all file structures from the many DLC compiled and superfluous files cleaned out it would go a long way to making it desirable for me to mod the game rules more.
As for the changes in Retribution... I mostly approve. I'm on turn 200 of my first real run-through of the game.
1) Pacing is much improved, specifically hull sizes, engines, and weapons.
2) Hypergates definitely help end the game sooner via conquest/etc. and I love them.
3) Population changes don't bother me... it is much more realistic, and construction has little or no reason to be tied to population once a civilization has an appropriate level of technology and automation. I DO think it's too little growth right now, but in my opinion it only needs tweaking, nothing truly drastic. Perhaps doubling the current base growth rate.
I have many criticisms I could bring up about GC (Because I love it so much) but none of them are specific to Retribution and most of it I probably couldn't fix with mere modding. So GRM will avoid making those changes and leave it to the user to pick their own "path" to follow.