This is entirely up to you, but I would worry that he would let others know that he gets a discount. Then anybody he refers would be asking for the same treatment.I have charged my repeat customers the old prices once, while telling them that pricing has gone up but I'm not raising theirs until the next order. I haven't had any issues as yet.
Sometimes mine come out short. Other times they overflow the pan and cause a mess in my oven.I've checked and adjusted oven temp, always have room temp ingredients, tested my leavener (yes, it has come out different heights out of the SAME JAR of baking powder).It drives me nertz. I wish I could figure it out.
They will hold up well in the fridge. If it stays cool they hold up well. You can't let them get hot, but you can't let SMBC get hot either, so I think you'd be fine.I've seen lots of pictures of roses made with modeling chocolate, so I know it is doable.