Hello @fair

I agree that some type of balance has to be introduced, as well as the suggestions you made were made by others before.
The issue with it is that it's extremely hard to balance everything out for everyone to enjoy...

A few issues with one of the suggestion is limiting people based on levels... As you say lots of high levels join one team.
That's not the case in all servers, you can find some that are fairing fine in that regard.
More so, by limiting people based on levels, you'd limit the player from playing with his friends if he wants to. (Both high levels get split into teams), which isn't good at all.

Concerning the idea for vehicle limitation to a specific amount.
The issue there is that players will start hogging specific types of vehicles, and others will be unable to use them the whole round.
As well as some might abuse said fact as to limit the enemy team (Switch teams, buy 2 vehicles that are limited), and just hide em or just cruise around for the round.

The better suggestion would be introducing something that'll help the vehicles survive longer, or become more bulky.
My biggest beef with ArmA 3 is that AA's are kinda useless compared to ArmA 2.. Tunguska's, Shilka's, heck even the Linebacker were insanely efficient.

Currently there's a vehicle limit in effect that simply limits the amount of vehicles ratio 1:1.
So until one of the enemy teams purchases the same type of vehicle, the other team can't get a second one
My suggestion to not allow a certain team to stack up on said vehicles until death, is if it's no longer 1:1, meaning before it was 3 jets vs 3 jets, but then one team looses 2 planes, leaving it 3 v 1, to balance it out on rearm the enemy plane will get refunded as well as the player teleported back to spawn. (Similar how the C130 on RHS is able to be refunded when landed)

All in all, your suggestions will surely be taken into account, and big thanks for your feedback on here, i hope more people start making posts on here, as it's very good to keep track of issues/suggestions/ bug reports.

Thanks for the answer! I would like to add even more convincing.
When I thought about these changes in balance, I also thought about the impossibility of playing with a friend. But nevertheless, I wrote because in the present balance there is also such a problem - sometimes the balance asks you to go to the corresponding team and after a while you can still change the command, but sometimes the balancer hard points you to a certain command and it cannot be changed. But despite this, friends still play together changing the team. Therefore, the separation of high-level players will also not become a particular problem if friends have successfully playing with an existing problem. In addition, a small percentage of players has level 100 or more. In addition, friends may have different levels, for example, 58 and 100. 58 will be able to choose any team. And even if both friends have level 100, there is still a chance that they will play together. So a small chance that would cause inconvenience to friends.

And what about the planes. Even with the existing restrictions, players still experience this inconvenience - the inability to buy a plane when they want. So it will not be a big problem - everyone has become accustomed to it. To achieve an adequate game with a good balance, it is necessary to limit the players, it is inevitable. In addition, in the existing system, the co-pilot cannot buy a plane for himself if other players do not have airplanes. It would be possible to make this restriction only quantitative (2 aircraft) and without depending on the number of other aircraft.