Scenario 1: No. Even if I was willing to suck a guy's dick for a pound of weed, there's no way I could keep that hidden in my cell.

Scenario 2: No. I couldn't kill someone unless I felt my life (or the life of someone I care about) was in danger, or they did something really really horrible to deserve it, like raping babies. Just being a bitch isn't enough to make me kill someone, no matter what the reward is.