Swype is trustworthy... It does collect anonymous usage data, but it's well obviously anonymous, and they don't go stealing your passwords and stuff like that. It's all spelled out in their EULA.
In fact, I'd hazard a guess that any of the extremely popular keyboards out right now could be trusted. If they were stealing folks account info people wouldn't be using them. People, and especially people in the Android community tend to notice when things behave badly.