Re: Leaving power on to pedals won't hurt anything, will it?
No, won't hurt them, how long has your alarm clock, TV, DVD (Blu-Ray, whatever) player, etc... been plugged in? And they are probably drawing more power than those pedals.
FWIW, the Onespot is a switching power supply, not an old transformer/rectifier style power supply, so it probably isn't warm either, and will probably outlive you even if you leave it plugged in. If it had a constant draw that was constantly pushing it to its limits, yeah it would warm up and it's lifespan might be shortened a little, but those pedals don't even tickle it.