noble, i will be interested to see the responses you get from Q's 2 & 3. but, i am having the same issues with Q 1.
i think the whole goal is to stay in position. if you have an SC and limpers, you will still be out of position against pp's and limped A's a lot. i would call for cheap flop b/c of position in a loose-passive game. but, i would raise it up 6-8X oop if the table is full of nits.
i am finding some floaters too, and we have to get better at distinguishing them and not cbettting them.