I'll start with the easy one - Oshae. Players can announce, attend tryouts, etc, without signing with an agent. Lots of kids with pro futures do this the year before they actually want to come out so they can be evaluated by pro scouts and learn what they need to do in order to boost their draft potential. That's simple enough for you to still follow. Here's where it could get tricky. What happens if he shows really well in the tryouts and gets told he may go top 15? He gone. Do I expect that, not really. But it's possible.
Next is Marek. He's from Europe, he's had success over there (FIBA), and I think he has to realize his game isn't suited for the NBA. So, he could stay here, have to take classes, and live under JBs rule, or he could go back to Europe and live somewhere awesome (hi Spain!) and get paid to play basketball for a living. And maybe even in a place where his first language is the spoken language.
Moyer, that's just a guess. I'm hoping that whatever transpired this past weekend can be resolved, because we do need bench players, and he fills that role nicely and with energy. But he also sees better players coming in next year who may reduce his playing time further.