[electrical]

A raise on Third from a dead Trey signals a big hidden pair or Ace-high three-flush, which will make it very hard for you to get any action if you improve, but will also allow your opponents to correctly value bet you/raise you on later streets unless you catch the case card.

I like a limp on Third, because a longshot paired door card could mean very little to your opponents, and catching an Ace wouldn't make anyone too nervous either.

You caught perfect on Four, so consider things from your opponents' perspective. Being out of position you (hero) would be compelled to bet a lot of not-that-great hands. They are likely calling along with weaker hands than you would expect had you made a raise on Third.

Betting on Sixth is a must. If somebody plays back, you can call down (remember that you have undersold your hand), raising if you improve.