I've really enjoyed a lot of the thoughts and ideas put forwards in this thread, whilst I doubt a lot of them will not come to fruition, it's still quite nice to be optimistic.
I'm personally a big fan of playing all our different sub-factions in both Coalesced and Starborne even if some are more optimal than others. I feel they all have unique gimmicks and tricks that are entertaining to play and I know my regular opponents are equally frustrated and excited when Starborne shenanigans are pulled.
Some of the things I'd like to see, which I'm sure echoes what has been said before, is making our less played units more playable. Saurus warriors as an example, I would like it if they could do in melee what a fully reinforced Skink unit does in shooting with similar buffs, either from Saurus heros or Skink heros.
For our other battle line, like Knights and Guard, the cavalry could maybe use a bit further movement, maybe some rend on their spears or damage on the swords to buff them, but overall I like the roll they currently fill and generally don't think much needs to be done to them. It doesn't bother me that they move the same speed as Skink, in fact I'd rather they didn't encroach on the speed that Terradon and Ripperdactyl riders have.
It would be nice to see Guard back in the role of immovable meat wall rather than ablative wounds for a Slann, but I think this could be done with some better buffs from the Eternity Warden to bring them closer to the old Eternal Starhost (not necessarily as strong as it was, but some aspects of it as commands would be nice).
Generally where I feel our faction really lacks is with our Saurus heroes. I don't think I've seen reason to really take any of the on foot heroes since 1st edition and the damage of our mounted monster heroes really doesn't match up to the damage output or durability of other factions beat sticks. A lot of the changes talked about here already I think would be nice to see, I'd like to be able to take a variant of the carnosaur that I knew would be a genuine credible threat rather than employing it as a distraction Carnifex.
I disagree with what has been said about Slann, or more specifically Kroak needing a better melee combat profile. He's always struck me as the Charles Xavier of our army and if he's finding himself in combat then I think better screens are needed to protect him. He's a monster in the hero phase, he doesn't need to even be good in the combat phase in my opinion.