Can I resolve all special effects or just 1 at a time in turn with other players before and after bases score
Can I resolve all of my multiple special effects when it is my turn, or do I only resolve 1, then give the next player a chance to, etc.


It depends on whether


  start with the current player and go around the table clockwise until all players pass in sequence


means


  Start with the current player. They may either play a card with a Special ability or pass. Go around the table clockwise until all players pass in sequence.


or 


  Start with the current player. They may either play cards with a Special ability or pass. Go around the table clockwise until all players pass in sequence.


There's no telling for sure without an official answer (which I can't find), but it seems more natural to me if the players only got to play one at a time.

You are definitely able to play more than one, but I believe you must give everyone else the chance to play one in between.




  Also, if I know a player after me has 2 effects, can I wait until he does both and then resolve mine (essentially passing then choosing to resolve)?


You can, but it's a gamble. If you pass, and someone else plays a Special, then you get another change to play a Special. This is explicitly mentioned in the rules. However, if you pass and he decides to pass instead of playing his second special, you won't get to play anything else.