I think you can get Open Street Maps in the F Droid app store. But, as much as I appreciate OSM, it’s just not the same as Google maps. The speed, accuracy and information doesn’t seem to have an equal.

You definitely can run Nextcloud in a VM. With decent hardware, it will do it. I guess I would say it depends on needs and expectations. My install is not snappy to me. I’ve got what I feel is a very beefy server but still. Just feels a little slow at times. Totally functional. Just has a small amount of lag when doing anything. I’ve read people say they have none at all. But when you’re busy and relying on it, my suggestion is to eke out everything you can for it for a better experience. Not make or break by any means.