Raise or push?

[Qar]

Hello,

I've read through the anthology and several books, but I'm still a bit lost on the following: say you have 2k chips (10 x BB), blinds 100/200.

CO you get 66: do you push or raise? What if you have 2400? 2600? Push or raise?

Same hand, you are in the hijack. Push or raise? What about with 2200, 2400, 2600?

What about CO-2. Hand again 66. 10 x BB stack. Push or raise? 12BB? 14BB?

What about something like KQs and the same scenarios? And what is the definition of being pot-committed? What if you have 2000, you raise 600, BB calls. Pot is 1300, you have 1400 left. Are you pot-committed here?

I think I sometimes misplay there situations, so...any good guidelines out there from our MTT pros?

Thanks in advance.