I say friendly fire OFF atleast in search and destroy. No one wants to sit out two rounds because someone on your team has some beef and wants to spend his time tking you till he gets kicked. You said it yourself that you want realism but fun should come first. Tking = Not fun
Hardcore should be mainly about more bullet damage and no hud, etc.
Also one of the stupidest things in MW2 was getting killed by your own airstrike because one teammate was in the enemy's spawn. So if you do decide on reflect, atleast take friendly fire off with killstreaks. I would be ok with that.
Keep the 3 teamkills and your kicked from the game ala WaW.
Only change I would make is don't let teamkills from Killstreaks count towards you getting kicked. I can't tell you how many times I was kicked because idiot teammates would run into my air strikes and get me kicked. You should only get kicked due to kills from guns, grenades, launchers or equipment. Also, since there is host migration, if the host is teamkilling please let him get kicked.
I would also like to see some sort of punishment like losing CP for those kicked from the game.
Definitely make it so you get kicked after X amount of kills. Shared is just plane stupid... I don't see what the point is. I think team killing should be kept part of hardcore. There is a level of skill required to make a quick judgment call between friend or foe. Maybe you could implement a sort of forgive or punish system. If you accidentally kill a team mate, he/she has the option to forgive you or punish you and if you rack up too many punishments, i.e. 3, you would be kicked from the game. If I'm playing with a bunch of friends and a bad nade lands at their feet, they would forgive me and play would go on. I feel that this is a fair and balanced way of keeping team killing in the game.
LEts Change it a bit, Reflect is simply a dumb idea, if at the end if reflect is the one chosed, simply disable teamkill. It puts me into rage mode when im shooting at some dudes and some stupid team mates runs into my bullets and kill me... when he should be the one killed . + Whats the point of making people mad when you could simply disable it and everyone is happy?
IMO the best choice would be that teamkill is disabled in the first 20 seconds of the game, then it would be activated but you get killed for n number of teamkills.
btw DISABLE GRANAID LAUNCHERS IN SnD PLEAAAAAAAAAAAAAAAAAAASE