Profile of Hannibal

Changing it's role completely to a howitzer could be interesting, but let's be realistic: 1. It's difficult to not make it redundant with the Katjusha. 2. The game is waaaaay too old for that. We should aim for simple, yet effective solutions.
Soviet T3 actually has a good unit mix. AA/AI-support unit. AI specialist light tank, AT specialist light tank. The SU76 is not an unreliable unit, but there are cheaper ways for Soviets to get the same performance by back-teching and buying a ZiS. So the problem is, as correctly stated previously, the cost/performance ratio.
So we have two options:
1. Make SU76 cheaper -> In my opinion a bad idea due to how many problems this could lead to regarding spammability and suicidal dives by using it's long range.
2. Make SU76 stronger -> In my opinion the way to go.

The earlier SU76 had mostly reliable hit/pen chance against a P4, 160 damage and 60 range plus a free barrage. The new version got accuracy nerfed and damage nerfed to 120 damage, which means 6 shots to kill a medium, plus an expensive barrage.
Upping the damage back to 160 could lead to random P4 RNG kills in a the 2v1 situations that the Axis player will likely face. So I'm not sure if this reversal would be so great or not. Lowering accuracy could counter that but makes the unit frustrating to use and fight against for both players.
As a first step to test how to get SU76 back into the meta, I suggest to give it a timed ability (heat shells) that increases damage to 160 and maybe penetration as well for ~30 mun. Also make the barrage ~20 mun.
In my eyes, SU76 could be mediocre unit for standard use that can be boosted to a strong TD or artillery piece if you pay muni in the correct moments. Due to the munition sink that a SU76 will be, it won't be spammable, but might fit into more builds since it can be very useful and be "a poor man's SU85" as originally intended. Also we would preserve the Soviet theme of utility with multi-purpose units.
This could come along with minor cost adjustments. If it's enough, we keep the unit like that. If not, we can discuss if we make stat buffs permanent.

Actually not so many unit need access to it.

The ability should definitely be replaced from Stug -E.

It could also be replaced Puma or even the Elefant.

We surely can discuss about this, but at the moment I don't think that any version of TWP is overperforming, so for start a simple name change would be nice.

Suggestions:
- turret lock = target turret ring
- blind = target vision slits (would explain that the driver can't drive due to panic and missing orders from the tank commander and gunner can't see the targets)
- stun = target weak point (there's no real logic for that ability though other than the crew panicking)
(what other versions are there? can't remember)

Changing/removing abilities might cause other issues with the unit that uses the ability and could be a project for the long run.
And to get to your points: What do you want to replace it with? Or do you mean remove?
I do like a TWP ability on the Puma (funnily enough I can't recall if the Puma has a stun, blind or something different). It enables the Puma to be useful as a support unit even after the medium tank phase has begun, just like the Stuart.
StuG could do with a blind in my eyes (not sure what it has at the moment), since the PaK already has the stun. Elefant's TWP could also be removed in my eyes.

Had something very similar as I tried new Rangers with super bazookas. They got halfway supressed by MG (yellow supression not red one). I could select the unit and see their unit portrait in the hud but it had no abilties or action buttons, the Retreat button was missing too. Only after smoking the MG and rcovering from supression they could retreat. Strange error that I couldn't reproduce afterwards.

Happened to me once too and saw that on VonIvan's stream as well

Not going to close the thread because it may be a legitiment problem for this player. It's not like the majority of the posts in this thread have been even remotely helpful towards OP. :/

Start by narrowing the field of concern from the OP. For example, we don't know what gamemode they're talking about. Jacksons are problematic for example, but they're more prominent in teamgames than 1v1.

What gamemode are you talking about? What are the concerns you have about allied armor? No armor piece is instant win, although some are stronger than others.

I've read OPs post again to see if I missed something. Your good intentions in all honor, but OP is just ranting. The only part that comes close to a discussion point is:

As for axis heavies (including the panther), they are having an extremely hard time escaping the Range/RoF/Pen/Damage of allied TD, the most offfending one being the Firefly due to its retarded damage and range. Su85 is also broken, with its selfsighting trick and HMG-Like RoF.

This is something that surely can be talked about and there are multiple threads on that subject (one is running just now). It even does not matter if the stuff he describes is objectively correct or not, but the post is just another "Allies OP!" and "Axis OP!" that we don't need. Nothing that would promote a discussion, only very faint and few arguments if at all. People are not helpful because OP does not make a legitimate and honest effort.

Could a mod please close this thread?
It's probably just a troll post but even if it isn't it's not a proper contribution to the current discussion by far.