You shouldn't be running binaries you don't trust no matter where they come from :) . And honestly I would probably use the MS store if it didn't suck balls.
Seriously whoever designed their "modern" UI needs to get booted. It's terrible and the main reason nobody uses the windows app store.
Ubuntu, MacOS, and even Steam on Windows all have a good app store interface. MS designed the OS and their version is a UI nightmare.
I'm hoping in some way there's some MS employees watching this thread. Please fix the damn app store by just extending the functionality of "add/remove programs" which everyone knows how to use and works fine.