The best thing to do, assuming that nobody wants the lordships long-term, would be to not appoint anyone in the first place.
Bingo.
1. If you did have automatic elections, then they will automatically kick off, every 3 days, for eternity. We get enough message spam already, don't we?
As soon as your temp lord resigns, you'll get another election. So what's your point?
2. There's no way to align the regions to a duchy without appointing a lord.
Newly captured regions are automatically assigned to a duchy. There are no more "imperial" regions.
