A. The only dumb question is the one you don't ask.
B. I've had good luck stripping what little acrylics I've stripped with a Car Quest product called Purple Cleaner.
If you're stripping enamels, try a spray on oven cleaner (Easy Off comes to mind). Wear hand and eye protection if you do because it will certainly let you know you have it on you! Brake fluide works very well but leaves you with a disposal problem.
C. I use enamels (Model Master and Humbrol) for the majority of my painting and for the past 20 or so years have used DuPonts 3812S enamel reducer very successfully. It is sold in quart and gallon cans. I buy the gallon size - cost 18 to 20 bucks a gallon. But a gallon will last me up to a year and a half.
And lastly I would like to make a comment on the use of a respirator while airbrushing. I've seen some statements on this forum to the effect that "If I'm spraying enamels or laquers I always wear a mask" and "I only use acrylics so I don't need a respirator" I personally believe that these people are wrong. No matter what I am spraying, I wear a respirator. Never mind that acrylics are not near as damaging to your lungs, they are a foreign material and your lungs are not designed to be coated with a foreign material. I also wear a respirator when sanding paint or resin coated objects. In fact if I have any question in my mind whether I should be wearing a respirator while doing something, I wear the respirator. (Sometimes you have to learn the hard way - I worked for 35 years around radial engines and big bore rifles without using ear protection - now I've lost about 75% of my hi freq hearing in my right ear and 40% in my left - just because I didn't take precautions early on) Sorry about the rant, but to me there are very very few things in the world (and especially in a hobby) that are worth damaging your health and well being for.