If I had a nickle for every model I've had to just chalk up to experience, I'd be a wealthy man right now!
There are two combinations you mentioned in your post that spell trouble: Beer & No. 11 Blade. Believe me, Arterial Red makes canopies look like crap too! (not to mention your fingers!)
As far as the Future goes, I'm not sure you can remove that from a clear piece without glazing it beyond use. If it were me, I would let the canopy dry really really good, and vacuform a new one, using the bad one as the mold. It's not a hard thing to do as long as you do it before too many beers.
Here's what you'll need:
(1) One piece of clear plastic approx. 4" x 4" (top of a greeting card box)
(2) A Candle
(3) Little ball of molding clay
(4) Wooden kitchen match stick (one of those 2" long matches)
(5) Piece of #0000 Steel Wool
(6) Fine point Sharpie Permanent Marker
Then you....
(a) Use the steel wool to completely smooth out any lumps or dried dust fibers on the canopy you messed up.
(b) Put a ball of clay on your desk and stick one of the matches in the center of it, sticking straight up.
(c) Put the other ball of clay inside the canopy, and place it on the end of the match stick that's sticking out of the clayball on your work desk.
(d) Set your candle on your desk about halfway between you and the old canopy, and light it.
(e) Now take the 4"x4" piece of plastic and hold it on each side.
(f) Now hold it about 3" over the flame, moving the piece around in a circular fashion, until the center of the plastic begins to sag.
(g) IMMEDIATELY lay the sagged clear plastic on top of the old canopy until a perfect duplicate is made. **DON'T press it down too hard, or the upper surface will be too thin to work with**
(h) Before removing the plastic from the mold, use your Sharpie to trace the CUTTING line, using the old canopy as your guide.
(i) Remove your new canopy from the old canopy mold, and carefully trim along the cutting line.....
Walla..... new canopy!!
Hope this helps...... Oh yeah... I never ran Future through my airbrush, so I can't help you with that. I've always dipped my clear pieces in a paper cup full of Future, then let them dry under an upside down glass to prevent dust settling on it while it's wet.
Take care and good luck my friend!
Frank