I think it's pretty insulting and elitist for you to say this game isn't for someone just because they pointed out there are downsides to something, especially when you don't even know what those downsides are. I know perfectly well what this game is and basically saying "go play battlefield instead" is a very poor attitude to have towards someone who just wants to discuss a new aspect of the game.
I'm all for stopping players just taking a vehicle and ruining things for other players by being selfish, but restricting them to that degree seems like it would have some pretty significant negatives to it.
Giving squad leaders the responsibility to decide who gets a vehicle and needing both them and 2 other squad members to use one severely restricts a players options. Doing that isn't suitable if those players are halfway across the map and the team needs a logistics vehicle to provide supplies, for example. It results in situations where a squad may be on one side of the map needing assistance, yet vehicle support won't be an option without a squad leader going all the way across the map to get it, basically abandoning the rest of the squad for a while. Or another example would be several non-SL players from multiple squads who just respawned at the main base and then are unable to use a transport and have to instead wait for a SL + 2 members from the same squad to respawn there as well, or walk. Sure you could just say “It's a team game, just forget about it and wait for someone else to take it” but that takes up significant time waiting for that to happen even though there might be perfectly good players who could do that task already, but just can't because of that restriction.
It also means that you can't do things like have players decide to run logistics without taking up a significant portion of squad members just so they can start doing that in the first place. They could set up their own squad and be the SL, but then they'd have 2 squad members (if they could get them in the first place) who wouldn't have an active squad leader, so that would be 2 players who aren't going to be very effective. Joining a server and deciding you'd like to transport squads around or drive the logistics vehicle when needed will not really be possible without a fairly significant portion of your squad taking up time just to let you do that. It could quite badly limit players from doing the roles that they'd like to do. At the same time though, I can see why that's there. Players SHOULDN'T be able to join a squad, decide they're going to do their own thing and just run logistics or transport or whatever when the rest of the squad wants them helping out instead. While requiring 'permission' gets around that problem, so would kicking a player if they were being uncooperative.
Having certain vehicles (assuming this will work for MBT and such later on) would also limit their ability to respond to situations and assist the rest of the team if needed, as rather than being able to directly communicate with that vehicle, it instead has to go through the SL if they aren't the one using it (i'd hope the SL wouldn't be the main player using them, anyway). That's not really a big problem but something like making certain vehicles (obviously something like a humvee wouldn't need to do this) their own classes and squads would solve that issue, at least with MBTs and such when they're added.
So no, I don't want this to be like battlefield where players just grab a vehicle, drive off without the rest of the team and end up wasting it, but at the same time it would still be good to let players not be so limited with their options. Obviously just letting anyone grab a vehicle whenever isn't the right thing to do, but I don't think this is the right way either from what's been said so far. The claim system is good for stopping someone just driving off with a vehicle that a squad is currently using and that part of it is great, though.
Maybe I'm wrong and things won't be so bad, though.