Very interesting to see a discussion regarding the difference between MP1 and MP2. I have tried to solve this problem by considering MP1 to be EP and I refer to it as the "fence" as in "sitting on the fence" meaning it can be EP or MP depending upon game texture and the action thus far. The way I actually do it is to look backward from the button. Button and cutoff are LP. Next two are MP. Then comes the fence and three EPs.

Wes' comment on folding all of those hands is interesting and probably relevant for a tougher game than what I usually play. I am still by far the tightest preflop player in my game, however.

I am currently open-limping A9s and the lower Broadway suiteds from the fence. I open-raise AQo and 99 here too.

A3s is a clear fold for me here. I might play the small suited aces in LP but only with many limpers in front. In LP I might steal-raise with it but conditions would have to be right.

Small pairs (below 99) I usually limp to flop a set with many limpers in front or steal-raise (or isolate one limper) when late.