Small blind vs. steal raise in a 2/3 structure

[SinCityGuy]

I've been doing a lot of thinking about playing the small blind vs. a steal raise in the 2/3 structure that is common at 15/30 and 30/60.

Here's what I've generally been doing, and I don't know if it's correct. Unless the BB is a weak player, I 3-bet or fold. If he's weak, I tend to cold call with more of the marginal hands that I would defend the BB with. If he's a decent player, I don't want to give him 5 to 1 odds to come along, so I either fold or reraise.

I don't know if this "fold or reraise" mentality is correct when you've already got 2/3 of a bet in. It's obviously more straightforward in a 1/2 or 1/3 structure.

Also, how would you adjust your standards if you were first to act in a 2/3 SB after a non-steal raise? I think you've got to 3-bet or fold, but I might be wrong.