I think you touch on issues well but I'm not sure I agree with how you go about it, so I'll list my concerns under your general headings:
Infantry Section: Indeed the med pack is clumsy, but on the upside it both promotes the employment of UKF as a defensive faction that must stay together to be powerful, and also gives a cheeky heal out of combat. The artillery is just stupid, I definitely agree, you have to be in spitting distance just to fire it. The increased squad sizes is not a noob trap, it's incredibly useful as it means the difference between being able to capture setup team weapons, survive sniper fire, do more damage etc.
Universal Carrier: Not fantastic early on damage wise, but good at harrassing, pressuring, transporting and thus in this sense it's a nice way of applying pressure that otherwise does not exist early on. The flamethrower upgrade is just a no brainer. However it's not a super tank-car thing, no, it has it's weaknesses early on, but it's all about maximising and capitalising on it's window.
Lack of Options: Options? You mean rush Bofors or wait a few minutes to bunker up first?
Indirect Fire: It is an odd thing, but considering how strong the emplacement is do they need something mobile?
I like where the engineers fit, interesting to not have vanilla mechanics not repeated.