Dunno what you want to do about the switches. You could do as you suggested, and it will waste zero power having them permanently "on" (just like every other outlet in your house!).

The next owners will want them, if you care about stuff like that (we don't normally).

It is easy to rewire the outlets themselves so that both halves are permanently on, like "normal" outlets, regardless of the switches. And easy to later put them back to switched operation again.

The only thing you cannot do, is bury the switch boxes into the wall with plaster over them. Okay, you can probably also do that if you totally disconnect the live wiring that goes to them first.

Cheers