I do agree that the aura shouldn't become stronger with vet.
However, I have not yet seen a command panther past vet 2 (luckily) so I cannot really comment on how strong it is, but judging from the stats in the game it is indeed very strong.
The concentrated fire ability however seems too strong for the cost.
The commander it comes in is a bit of a mis-match, seeing as it has an upgrade for obers which need to be build in t4, but also a call-in which rather replaces a same unit out of t4. The point here being that taking full effect of this commander requires t4 which deminished the effect of going for the call-in command panther.
I agree that the commander is a tad odd in that it encourages to forgo t4 because you can get a superior panther without the need for the tech structure. However, I would argue that the argument regarding the diminishing effect doesn't really hold since the difference in cost to a vanilla panther is 25 fuel and 70 manpower (completely neglecting the cost for t4), hardly anything that would make you think twice and it's hardly anything that would prevent you from getting t4 either before getting the command panther or after. The difference can be more of a hurdle in 1v1 but in anything else, the difference is not a big hurdle.
The only other issue I see is that the unit scouts for itself and doesn't require any unit for support. This is okay for scout units like a puma, stuart or t70 but for heavy units it defeats the point of advertising combined arms.
4) agreed