Openvpn uses a type of encryption similar to ssl. This seems to suggest that even if I choose an incredibly shady VPN server, then my content will be secure. That is, the VPN server will be able to monitor what websites I patronize, but not the actual data I transfer.

That said, I am not an expert at this type of thing. I wanted, therefore, to make sure that I understand correctly. Is it true that if I use openvpn that my username/passwords are secure, even if the VPN is untrustworthy? If not, why? (And how, if at all, can it be fixed?)

Examples of things that I don't know much about that may (or may not! I honestly don't know much about this.) be related to my question are: DNS leakage, IPv6, tracking cookies, browser plugins and websites that don't support https.