General 5-max starting hand question

[jenga223]

Hi. Long-time lurker on these forums.

In the 3/6 5-max game at WPEX, I will sometimes fold marginal hands like KJo, KTo, KTs, KQo, AJo, A9s, A8s, 22-66 under the gun for whatever reasons. Sometimes I'll be running bad and don't want to be out of position against a tough LAG who constantly 3bangs me and puts me in difficult spots post flop. Or I'll have just showed down a couple marginal hands in a row and want to slow down.

Anyway, is not playing these hands a leak? if so, which ones? Is it okay to fold some of these, but not others? Also, the same question applies to raises in front of me. Sometimes I will 3-bet these hands and sometimes I will fold. Lastly, the SB is 1/3 the BB, and sometimes I will fold these hands to a blind steal instead of re-raising (sometimes I will call, player-depend, I know). But am I missing out on substantial EV by doing this?