Just to clarify "PAM" means "Provent-A-Mite" and does not mean the cooking spray.

Snake mites are not a native pest, so it would not have picked up any being loose in the house, unless you already had a mite infestation. If the mites you saw came from the cypress mulch (always a possibility) then you're probably done messing with them. If they were actually snake-mites that came with the snake, then you may have new ones hatch in a few weeks and the P-A-M will help ensure they do not come back.

Aspen is ok...but so is newspaper. If one is relying on the bedding to maintain humidity, then the enclosure isn't properly set up anyhow. You want the air to be somewhat humid...you don't want the bedding to be wet.

If you can give us some more details on your set-up, we can help with more specific suggestions. And you can also get some really great guidelines from the Caresheet.