Will the Pi CPU mine by default with minepeon? Mine has been sitting in a case mining for the last 3 days, not tinkered with the mining options, any danger there?
Yep, it is configured to CPU mine by default so you might want to open the case to give it a bit of air.
I have to admit though, I was pushing mine very hard to see what the tolerances were like in order to set alarms in MinePeon (over-clocked to max, with a heater running in the room) so you 'should' be fine.
CPUmining is bad for overall performance too since its cache trashing and it also introducers more lag for cgminer/etc, thats is a really bad idea...