I hardly ever play 3 handed, but if I do, it's because I know my opponents well and I know they're bad. Without reads, I'm clueless here.

As a general assumption, button open-limpers are usually Loose Passive. That means the best way to play this hand in situation 1 is to just check and anticipate a free card fairly often. If the limper happens to be TAG, then he's either A) limping with a monster, in which case you wouldn't want to get involved or B) limping with the intentions of seeing a turn, in which case you wouldn't want to get involved.

In situation 2, both types of players (LPPs and TAGs alike) will fold to a bet a good percentage of the time. The TAG will fold about 90% and the LPP about 60%. If the TAG calls, just give up instantly. If the LPP calls, you can fire a 2nd barrel and expect some good results. Unfortunately, if you don't know your opposition, you don't know which one you're dealing with, which is exactly why 3 handed is sooo difficult without reads.