The best seat in the house!.
...Maybe preflop as you do act last, but not post flop since you act second.
Sitting here you already have made a bet.
...No you haven't. You haven't done anything as it's a forced bet. There is a big difference between putting in a BB because you decided to and being forced to.
If the pot is not raised you have the easiest decision to make, check or raise. If you raise with a strong hand everybody knows you have a strong hand, and most will fold, best to check.
...I guess checking or raising is an easy choice, but you're way off on the 'checking because everyone will know you have a big hand and will fold.' For one, if there are a lot of limpers in the hand, you want to thin the field a bit with your big hands. Second, you're also looking at value to your big hands with a raise as well giving you better chances to win playing against fewer opponents.
If there are only a few players in the pot, raise to get more money in the pot.
...I agree with the raising to get more money in the pot, but why would you raise when you have few players in, but not when you have a lot of players in?
If you have a weaker hand, check and see if you can improve on the flop.
...You could check it, that's pretty standard.
Or, depending on your stack size compared to the blinds + antes, you could raise really big/jam it all in and pick up a bunch of dead money.
Just another option.