Should drop ear elbows be used with CPVC supply lines?
If its a short length of pipe and it's got a little wiggle room it shouldn't be an issue if you solidly mount them, but everything already mentioned (30' length of pipe needs expansion loops, over sized holes are good, allowing for some play/movement of the pipe is recommended) is good advice.   

And you don't want the pipe flopping around inside the wall. It will make attaching the angle stops and supply lines for the faucet a PITA later if they move around too much.