Since those keys are not "deterministic," then they will need to be stored in electrum.dat, I guess. Will they be encrypted in there?
Also, I think I found the wallet seed in electrum.dat. It's 88 characters, with numbers, upper- and lower-case letters and some special characters. Is that the actual seed, or is that an encrypted version of the seed that I would have to enter a password to unlock?
1. Sure, any imported private keys get encrypted as well. However please note that electrum doesn't support importing compressed keys at this time. There is a pull request for this but it still needs to be adapted to the current codebase and merged in.
Anyway, the best practice is to avoid importing keys as much as possible, and send funds from bitcoin-qt to electrum addresses instead (if at all possible in your case) - this is to get the full benefits of deterministic wallets.
2. That's the encrypted version of the seed (ending with equal signs). It can't be used without your password. The actual seed is a 128-bit high-entropy random number, which is usually displayed as either a 12-word mnemonic code or a 32-digit hex number.
Thanks again for the help.
No problem, always glad to help. I won't be online very much next week, though, but you can also get assistance in the
main electrum thread or on the #electrum IRC channel.