I don't know anything about T.Hawk but I'll give you my thoughts on some of those changes. First off, some of the frame data changes seem inconsistent...like they don't increase/decrease by the same amount. For st.hp, if it becomes -3 on block it should be +1 on hit. Shaving off those 2 frames comes from somewhere, either reduced recovery or additional hit stun, but regardless the changes should be uniform.
Fixed the one you mentioned. Let me know if you spot any other problems. I was inputting stuff and probably input the wrong numbers everywhere other than the ones I got from UltraDavid.
St.hp sounds like it would be too good. The only other character that has a normal that does 140 damage is Zangief but it's offset by having slow startup (his far normals) or punishable on block (his close normals). This change would give T.Hawk a relatively fast normal that appears to be unpunishable aside from supers. I could be wrong on that but what moves can currently punish st.hp on block at max distance?
Currently, Hawk's st.hp has 8 start-up, 2 active frames and has very little range to it. It makes it very hard to hit an opponent with it as a result. The effective range of it is probably something close to st.lp or maybe shorter and I think I've seen it whiff on crouching opponents on occasion as well. Gief's does does damage and has reach in exchange for its speed. Along that line I considering I thought the range deficiencies, low active frames, and recover on this normal would need to be offset to make it more appealing to use. UltraDavid had a similar idea though he reduced the recovery on it instead of increasing the damage.
For reference, T.hawk's crouching HP is 140 damage although it's two hits. His close hp and close hk are 130/140 respectively but don't lead to anything right now.
Changing his cl.hp doesn't seem to be changing anything. If he can link into cr.mk, wouldn't the Ultra changes give him some new combos regardless? Same thing with st.lk. It doesn't seem like he gains anything based on your description. In what situations would you use that button vs st.lp or st.mp? (I just checked the changes from the loktests and it seems there is less pushback from cl.hp)
cl.hp isn't getting reduced push back. It's cl.mp that did unless both got a pushback reduction and no one actually reported it correctly, lol.
cr.mk xx condor spire doesn't currently combo when hit on the tip of the attack except maybe EX (I'm going to test that next week) which doesn't give him a real combo, I believe. The change would basically give make his cross-up more dangerous in exchange for execution. As of the latest USF4 build, splash, cl.mp, cl.mp, dp is a combo. Reducing the knock back and frame advantage on hit for cl.hp gives him a heavier execution version of this combo. I'd definitely say that cl.hp could take a reduction in damage dealt in this case though, from 130 to 110ish so that it's a significant increase to a combo but not too overpowering.
There are a few implications to cl.mp push back being reduced that I just thought of though, hrm.
As for st.lk, it would be used in conjunction with his new walk speed to get in on opponents. st.lk doesn't have the advantage that st.lp does on hit or block but does have better range and active frames. I think it'd be a more ideal button to use. St.mp currently has longer range, better advantage and more damage, but is slower and has fewer active frames which really doesn't make it ideal for walking in on an opponent aggressively. Hawk can't get in on folks with better buttons because his buttons don't really apply enough pressure to let him walk in as needed. Giving st.lk the same advantage as st.mp makes it the better choice to use to walk in on folks because of how fast it is. it's not as good as st.lp but the range and active frames should cover it, I think.
Basically, the idea is that Hawk should have a button for the ranges he has to cover as he walks in. st.hk > st.mp > st.lk > st.lp should allow him a button for each range and the idea behind adjusting the advantage so you would want to use st.lp > st.lk > st.mp > st.hk as you get closer. That distance between st.lp and st.mp is rough for hawk, very rough.
You mentioned you wanted to further increase his strengths but that doesn't solve any of his problems and wouldn't really make him a better character. He has a lot of trouble getting in which is what the changes should be addressing. Improved walk speed, better condor dive, and more time after throws/knockdowns are the first thing that came to my mind.
Improved Walk speed is already in and the button changes I mentioned were with that in mind. He needs to be able to fend for himself on that front as he goes in. Better condor dive would be far too easy to mess up. It needs to be punishable on block and I think it's fine as it is currently. The UltraDavid changes were probably the best ones that could be done for them without running into balancing issues.
As for knockdowns, LP SPD's range buff helps with that but a bit. The real problem with trying to buff throw/knockdown time is that he doesn't have moves that actually hard knockdown at longer ranges thus allowing him to walk in. Ex. spire already helps him go through projectiles and adding a hard knockdown would be stupid to it. So it's really footsies that need to be improved for him. Hard knockdown for Dive would be silly too.
I'm mostly tossing some ideas out though. Hawk still needs buffs and I don't think a lot of folks really know where to go from where he is with the Alpha builds for USF4.