I bought the easy fps editor a while back for commercial use, can you still sell your game with this version? if not it's cool cause I'll mess around with it.
Yep, you can make commercial games with both the classic version of EFPSE (ver 1.6), and with the new EFPSE CE 1.10. The info is on the itchio page, and says:
"And to top things off, it's completely free!
You can release and sell games you make with this engine, without any payment or royalties."
Well to make a Hub world, you would have to learn the scripting system for EFPSE, which has a limited number of commands, but is kinda hard to learn (very few tutorials or anything online so you have to rely on the manual). So it's definitely possible, but I wouldn't say it's easy.