Hey Argent. I registered so I could answer you. I’ve spent WAYYY too much time in this game.
Let me see if I can answer everything. . .
“Stat-Padding” is spending time doing things that aren’t important to the game in order to gain experience points, usually so you can get a weapon unlock, or in some cases, have a bigger e-penis(stats).
A common example would be 3 people joining a server, with one of them joining say, the MEC team for this example, and the other 2 joining the U.S. team. All 3 get together in a remote corner of the map. The one person alone on the MEC team then ‘kills’ one of the two players on the U.S. team, thus improving his # of kills. The teammate of the ‘dead’ player then resuscitates his teammate, so that he does not suffer a death (in his stats). The ‘kill’ still counts though, and the teammate doing the resuscitating gets points for bringing him back. Lather, rinse and repeat for maximum effect. A bit convoluted to explain, but I hope you get the idea.
The packs left behind after someone dies is their kit. You can pick up their kit and have the weapons, ammo, and ability of that person, instead of the kit you chose when you spawned. If you don’t have all of your weapon unlocks, this is a good way to try out new weapons before you choose them permanently. Not sure if you want to get a sniper rifle or shotgun with your next unlock? Start picking up kits on the battlefield and maybe you’ll get to test-drive them. Also, you can use these kits for a momentary advantage. Say you killed a medic, but now you’re badly wounded. Pick up his old kit, throw out some med packs, and now you’re all healed! If you don’t want to play as a medic, just pick up your old kit again after you’re healed. This also comes in handy when you need ammo and you spot a support kit.
You know, I’ve played this game since it came out, and I’m not sure what key I hit to pick up a kit. It’s just instinct now, but I think it’s the USE/ENTER key, the key you press to enter vehicles(whatever you defined that to be).
If you die and are revived, ending up with a different kit, it’s because you died next to someone else who died, and the computer got confused and gave you the wrong kit when you were revived. I’ve seen cases where people were revived and somehow their kit was too far from their body, so they had NO kit. The player-characters run around with their arms out to their sides at weird, odd angles, so they’re called ‘scarecrows’. This is pretty rare, though. Also, if you die as a medic, some players will grab your medic kit and use it to revive you, but then they’re stuck as a medic(until the find another kit), and you end up with whatever kit they dropped.
The commander spams the comm channel for a few possible reasons. Maybe he’s trying to be helpful and no one is noticing the imminent danger that he is fervently pointing out. Maybe he’s pointing out everyone as fast as he can at all times in a (sometimes misguided) attempt to give as much intel as possible, or maybe he’s just a dick.
A lot of ppl who should be kicked/banned aren’t, and many who don’t deserve it are. It’s the internet. The best thing for a good game experience is to find a clan that shares your general feelings/ideals about the game. That way, when you’re playing on your server, you can shout, “I’m the god! I’m the god now!” as you swing your banhanner, like everyone else does. . . or maybe the shouting part is just me. 
I’m looking for a clan myself, since my old one gave up BF2.
Crap, I took too long typing this up, and got beat to the punch. I’m posting it anyway 