I like the turn bet.
We may still have the best hand because the heart draw increases both villains' peeling ranges.
Also, since we'd call a bet in this situation, it's better to just bet it ourselves. It would be nice to fold hands that could have more than 6 outs against us, and we don't mind being raised because we have a decent amount of outs ourselves.
I think the wildness of SB also changes the dynamic of the hand. If he was a normal player, then this turn should be checked because in that instance we would be at a slight equity deficit. As is, we have a slight equity edge, combined with fold equity versus hands that we could cause to incorrectly fold.
The KJo example is a pretty standard fold. I'd consider three-betting if the EP limpers were unlikey to call two cold back to them.
Short-handed, with one or two limpers against a frequent raiser, KJo isn't that bad to call with in the SB.
I think against a maniac it would be ok to call, but even against a frequent raiser I think KJo should be folded in that situation from the SB for a couple reasons:
-The dynamic of a couple limpers will shrink most raising ranges. KJo doesn't have that great of an equity against the better pre-flop Hold 'Em hands.
-We have a positional disadvantage.
Granted, our relative position is excellent for how we would want to proceed in the hand, but it doesn't offset the combined badness of our pre-flop equity deficit and our positional disadvantage IMO.