Any risks with letting the kids install these directly on the Deck? My preference would be to only let them load the games there, but it is a very soft preference.
That... doesn't give me too much confidence, then. I have a habit of wiping my computers and rebuilding from scratch every year or so. I don't want that habit with the deck. :(
shrug your games are on the cloud, your saves are on the cloud even. If you keep good backups of your non-Steam stuff, all you lose is an afternoon with a flash drive and the SteamOS ISO.