If you are copying your passwords into the clipboard, you've already failed at using a password manager. Might as well just use an unencrypted text file.
Depends on the threat. If you may have a keylogger than copying may bypass that. KeePass 2 can even spilt its auto typing between the keyboard and clipboard so neither has the whole secret.
I tried to do something more structured by enabling auto-typing or something (in KeepassX (not XC)). First thing I wound up doing was to auto-type the password into the next application, which was a chat program.