couple questions

i have my BP in a 10 gallon tank with screen top and aspen bedding..my question is with the screen top and tinfoil (with space around the edges) to keep humidity will the aspen get all gross and moldy when i mist? and also will he have enough room to breath or should i use a fan in the room?

As long as you have proper ventilation space in the top, and you're not saturating the substrate, in my opinion, I'd think you'll be fine. Just make sure you have a humidity gauge and keep tabs on it. If it gets to high, remove some of the tin foil.

I have mine 30 gal set up similar (i made cardboard, foil panels that are movable) and I spray my substrate every once in a while, I've never had a mold problem yet. Just keep an eye on it.

Keep about 1/4 - 1/3 of the screen top open, free of tinfoil. Misting the tank every few days shouldn't make anything moldy. If it is getting moldy, then you are either spraying too much, too often, or you don't have enough ventilation. A fan shouldn't really be necessary, but it wouldn't hurt.