Flankers, I am planning on making my mod as a sort of "unofficial" expansion pack for SoaSE. So naturally, I will do my best to incorporate it into official expansions.
Support Cruisers are the Yarlok (Interdictor) and the Minelayer (name to be decided) cruiser, the first one has those two mandible-like arms in front, the later has that great fin in the middle. Long range frigates look like a jellyfish with dreads... can't miss them really.

Killy_Blame, the colonize will look different, though only to a certain extent as possible to mod withing the engine constraints. I'd love to be able to change the textures of planets on the fly to indicate colonization and transformation, but sadly that's not possible right now.
WarxCriminal, the movies and screenshots are taken using the highest possible settings for SoaSE, so I doubt you can get even better looking visuals, though Ironclad promises upgrades in that regard for the core engine with the new upcoming patch, so we'll see.

HEX, the Xin have a vast interstellar empire that has been at war with
another even bigger interstellar empire for thousands of years, so I think they would eat whatever chased of Vasari for breakfast.

But in the Last Stand you only have to deal with a probing attack force, so no worries about them being overpowered.