Back OT:
- the hetzer could have a longer reload time compared to the stug (because it was so cramped inside)
Agreed.
- the jagdpanzer IV was very "head-heavy", thus it was hard to steer
I find the jagdpanzer already hard to steer, especially when trying to properly hide it on a forest treeline (eppeldorf, ie). Also, the already skiddy physics of the game make it hard to keep it stable after properly steering it, because it's so loong. Should it be even harder?
- also the loadout of shells could be tweaked, stugs had quite more room for shells than hetzers
Another good point, but I think the loadout is pretty good now: some SPGs like the marders have very little ammo. Have you checked all?
this way it would feel like you are driving that certain SPG and not just another SPG. it would also balance them because these suggestions are all nerfs to german spgs.
Implying that you know better than the devs about balance is not a good way to get to your point
- the churchill should have better climbing-performance on hills. i remember i couldnt drive up a hill on totalize with it, while a cromwell could.
- churchill with the 75mm gun needs more HE
Both of them are good points.
- the hellcat is unique atm, however the lack of a proper reverse gear is annoying
The hellcat reverse gear is a balancing feature. Just don't use it: keep going forward and turn around. As you said, it's what makes the Hellcat unique, and we need more uniqueness for SPGs, not less!
3) for immersion: radio communication in the background for german tanks and late war allied tanks. this would really give you the feel of being in a battle and cooperating with other tanks.
Radio equipment was an advantage over other tanks, and you want to turn it into useless noise: a disadvantage, decorative as it may be. Please don't, radio spam is annoying already when a spot spammer gets on the servers.