Re: Do I push this?
 

Clear fold given the stack/blind sizes.

Re: Do I push this?
 

both are easy folds because KQo just isn't that good. The first one is even easier because you have no FE.

Re: Do I push this?
 

KQo becomes much closer with normal stack sizes. I'd still probably fold, but it's close. One main reason to fold is that when its 4-5 handed and the +Chip EV between pushing and folding is close, yet there are other players who don't have that many chips, it often swings your best play from pushing to folding.

AQo and AJo are elementary allins in this spot as is KQs. I suspect pushing with KQo will turn out to be either very slightly +EV if your opponents have tight calling standards, or slightly -EV if your opponents are looser. So it's really hard to determine and you are throwing away the chance of having later +EV situations occur and of miracles like 2 players busting in the near future occuring.

On the cutoff it should be a clear push.