FWIW, the permissions thing is generally fixable with fstab entries or editing mount options instead of always doing chmod. The uid/gid and umask/fmask mount options are what you’re looking for. I think mint has a UI method to modify mount options for it’s auto mounter, but I’ve not used it in a while so I can’t be super specific. I’d recommend fstab for anything that’s always connected and the other way for things you plug/ unplug
Not sure why you think that. It really depends on the performance of the new parts. If they’re (pulling numbers completely out of thin air) 25% faster at the same TDP, then that’s definitely more efficient. At that point it you can just use PBO to tune performance down to whichever power envelope fits your use case