Panzers - I like the 3 moves. Keep the armor bonus. This is the game's latest UU - it SHOULD be good.
Ballistas - IMO, give them first strikes. The BALLISTA and whatnot.
Phalynx - Good as is, probably better as the spear.
Bowmen (maybe) - They do need a look. Interesting abilities would be available with hunting only, first strikes, higher base str, or starts with a promotion (something, not all).
Dog Soldiers - The game's best early anti-melee is resourceless, comes with a typical tech, and grants barb immunity and supreme choking. Don't touch it.
Musketeers - Allow them to start with combat I or drill I in addition to the 2 moves, and you have a good unit.
Jaguar - It's pretty awkward, but IMO has the potential to serve a number of roles. Easy woods III is the top one...IMO it's fine.
Hwachis - Catapults with melee bonuses ARE strong.
Impi - +50% against melee.
Holkans - First strikes?
Conquistadors - They're already pretty good. I don't know what you want from a unit that has 0 counters for some time after discovery.
Curracks - Improved movement, or free combat? It's a good naval unit.
East Indianman - Really shouldn't be touched. Maybe another approach is a completely different UU?
Gallics - Swords as a unit are underrated. Easier, more likely access to more versatile swords, which are sometimes AGG swords? If you want to see something funny, start them with guerilla II also.
Camel archers - First strikes. It's an archer unit supposedly, so why not?
Edit:
Panzer - A 3-move Pazer is overpowering IMHO. It would be the only natural 3 move unit in the game (I'd be OK with it if Mech Inf & Modern Armor got 3 moves as well). Give Panzers Mobility.
Gunships, which happen to be HARD COUNTERS to panzers, get 4 movement points. Any 2 move unit can outpace a panzer on defense. Overpowering? Nay. Only with a substantial tech lead so that you don't walk into CG II fortified infantry and anti-tanks, which forces you to come up with collateral or bombers...
The UUs are mostly balanced - the problem is the AI. If every AI didnt have feudalism in the BC's, the mace and catapult UUs might be useful. Program the AI to sometimes shoot for liberalism, and camel archers would be a whole lot better. And try using quechas against a human... All the AI use virtually the same tech path and strategy every game; fix that and this list will look a whole lot different
Agreed. The AI tech path is stale, I'd like to see more variety. Hell, even somewhat haphazard variety in tech path choices would be more interesting.
CKNs are a good UU with collateral and 2 1st strikes without any promotions-but they are not designed to be the do-all unit. They have to be complemented with units with CR to be able to take cities (cats/swords/mace) and protected with anti-mounted units.
Pro sucks but actually does enhance the chinese UU. You can put cover on them, and they'll be attacking cities more effectively than anything but well-promoted or AGG swords. Melee won't defend well at all (especially with the collateral) and archery units won't do especially well either. The two first strikes are material.
CKN is okay, but the problem lies in the Chinese. They have weak leader traits (assume no protective wall abuse) and a useless UB that is marginally useful for a cultural victory.
EXP is a pretty solid trait, and IND is useful if you're willing to play for power wonders OR failure cash (even on national wonders). Assuming the wall "abuse" away does weaken PRO somewhat (I have major issues with people complaining about using wallchops when the favorite civic blocking all civic switches and "self-closeness" bugs, not to mention worst enemy map hack detection exist. If you argue these things that still exist in 3.17 were intended, you have no argument against wallchop at all. It's different if you just want a challenge, so don't so it, though). But let's pretend you can't wallchop.
Even then, china's starting techs virtually guarantee a good start. You can hit both bronzeworking and writing with 3 techs, and most land-locked starts allow it. Good culture-press, fast early great person, and an excellent chance of defending yourself. There are very few civ/leader combos in the game where everything is good (Rome has great leaders/UU, just-ok UB...ottomans are actually solid all around...persia is pretty good...but basically after the TOP TIER civ/leaders china fits in with any other).