Yeah Im not saying all play there was correct etc...it's purely an example to try and illustrate pot odds. They are pots you could call, from a maths point of view. Scenario 3 I think a small raise may not be a bad idea. Most people from the table will probably call it again, and if not you already have the required pot odds. One thing is though you do not want to be re-raised. Well not unless everyone else calls all the re-raises as well. To be a nit picky bastard doc you suggested raising 5-10, you couldn't raise 5 as that would be an under-raise, the minimum raise would of course be 6
Scenario 4 you'd have to judge your man. What is the $1 bet for ? Does he want a cheap card ? Is he trying to slow play a monster ? Has he got a pair of 6s ? A bit more info on the person would probably be helpful in deciding what to do. Personally I'd probably just call the $1, if you raise he might re-raise you back in which case you are in shit......as you then have no odds.
If he's trying to slow play a set it is of course awful play....you can call the $1 having odds and you might get a nice pay off if you hit. Even if you make the hand, he checks the river, you bet and he folds, you intially still had odds to call the $1 bet.