Wow! Nice long feedback post Etfaks! Most appreciated!
1) Elders and Purifiers (Relics) are actually neutral to everyone except Scourge and the other Relic faction, so their presence is just to show the old war between this three factions (the asteroid actually gets very close to Corvex

).
2) I mostly agree with you. Right now All modded factions have the same spawnrate (the same as TT, to allow Heg to be the dominant force in the system), but the JP have their planet so far away that usually their fleets get lost while traveling. The options here are mostly 2: move the JP spawn and stuff closer to the sun, or rise their spawnrate (but then they would be the only faction with this special feature).
3) About the small scale enemies: can't do much about it right now (I am deliberately NOT touching anything of original vanilla content), but I'll see if the spawnrate% of small fleets for modded factions is currently balanced.
4) I'd like to. In the first Scourge DEV release they were overwhelming, and kinda ruined the whole gameplay (most fleets were instantly obliterated), so I need to be really careful about that (fleet behavior is quite hard to control). I'd love have some good scripter on my side to help on this kind of things

.
5) Ship in this Mod will always be as vanilla-style as possible. I'm currently thinking about removing a faction that may not entirely fit vanilla style. We'll see.
6) Sure, I'll have a look at the Hoplites (I was already following your developments but, as you said, it went dead

.