What if I uninstall Fortnite on Xbox one? Do I still have my skins Us.w?
Yes, because your skins are tied to your account.
The skins are on your player account. This is independent of the installation.
Of course you still have your skins… Would be sad if you didn't have to start all over again.
There's no front or back. The game is a shooter o you can't lose anything. These skins are just money.