Last year I had so much trouble with mold on my cheeses that I didn’t even try to save and reuse cheese wax.  This year there’s no mold problem yet.  I’m thinking of rinsing the wax off in warm water and remelting it; can that create a mold problem down the line? does it depend on how hot I get the wax?

Yes it does depend on the temp.  I’m not sure at what point mold spores are killed, and someone on the forum can likely enlighten us on this.  I do know that I have reused wax that had come off moldy cheeses - ones that had cracked and gotten pretty bad - and there has been no recurrence of any mold.  You do want to be careful not to get your wax too hot, as it is a flammable substance.

If u maintain a 120F temp of the wax for 30 min, it should get rid of the mold, if u go to 140F it would be quicker but may damage the wax.