That's very hard to answer since it never happened to me; perhaps if someone experienced this, he can leave a reply on what happened.

My guesses based from the code: there's no transition from "CLOSING"/"FORCE-CLOSING" to "OPEN" so it's a no.
If it was force-closed by the other party, it will remain open in your client since there's no confirmed closing transaction.
Channel State Transitions: https://github.com/spesmilo/electrum/blob/master/electrum/lnchannel.py#L98-L126