RE: MONOKOTE PROBLEM
I use Monokote Trim Solvent, made by Top Flite. It activates the adhesive in Monokote without heat. It also removes adhesive (solvent) which also contains the color.
Just a little on a Q-tip, wipe away immediately with a dry Q-tip or paper towel and the color smears go away. Avoid putting too much around a seam between two colors, as it will bleed the color right out from under the film.
A little bit, that's all. Experiment and you'll soon get the touch.
Oly
PS. It also takes off any Sharpie layout lines you have. Rubbing alcohol will also take off Sharpies, but will not remove the covering color smears.