I’ve been taking part in the beta, as far as Steam is concerned me and my friends are a thrupple. Works pretty well, other family member’s games just show up in your library. Haven’t had any issues, Steam will tell you if your copy is in use by a family member and you either play something else or ask them to quit.
The difficult steps in FTL are no joke. I was having no difficulty clearing on easy and was just trying to unlock all the ships. Once I did I switched to normal and had to restart 3 times before getting out of the first sector.