I've almost never used the UC, so I didn't touch it (I don't know how to balance it). I don't think it's in a bad spot though, judging from its effectiveness in the tournament.
What do you mean with "nerf Infantry Sections", specifically? Decrease the stats of their SMLEs?
One solution to the Vickers suppression issue is to reduce damage, but I'd like to keep its uniqueness as an HMG.
Bolster applying to weapons crews is interesting.
My new idea is to give Royal Artillery the USF mortar HT (instead of the Pack Howitzer). I would say that it is definitely effective enough as an indirect fire piece, but leaving the AEC with no competition would probably result in the same builds that we see already (AEC nearly every game).
UC getting a fuel cost is the right step, it’s not good for the game to have such a strong no fuel T0 vehicle.
Infantry Section nerf is to bring them down in effectiveness into a balanced state where they are all around good but not OP. Certainly with 5man crews they’d need to be like 5man Volks with 1 STG in effectiveness.
Mortar HT would fit UKF like a glove.