1. Ability for heroes to be used in clan wars while upgrading.Already reported and strongly petitioned. Nothing more to say.
2. Ability to assign/claim an opponent base during clan wars.
I'm not seeing much on this one, if anything. It's a bit harder to search for this one. I don't see it in ruled out or already suggested, but I would be surprised if it hasn't been. That said, I don't believe it is getting the traction it needs, like the heroes one! This would improve clan wars significantly! This is not something that can be done with email, and not everyone can read every message to see who should attack who or called out a base. There are 3rd party apps for this and messenger apps, but this needs to be done in-game, not 3rd party.
These are two clan war essentials! These need to make it into the game yesterday!