Okay so this might be completely stupid idea but I will just get to the point. Lets say we make an extract of an herb using 91% isopropyl alcohol. You then need to wait for the alcohol to evaporate to collect the resin extract. Why can't you just light the alcohol on fire so it evaporates faster?

The flash point (heat of combustion) of ipa is only 35 C. Plus when you light alcohol only the vapors burn, so the goodies shouldn't get effected.

Is this a plausable way to quickly remove alcohol/ other volatile solvents from the extract?

The flash point is not the heat at which it burns at, nor like you say the heat of combustion. Also for IPA it is generally lower, 11.6 c. This means the lowest temperature it is capable of producing a vapor which is flammable.

The actual ignition temperature is higher, along with it's burning temperate, more than enough to damage the alkaloids.

DON'T IGNITE FLAMMAMBLE SOLVENTS LIKE THAT!
This is the single most irresponsible idea I have heard of, lately; by igniting solvents you damage both the extract and you also risk setting your place in fire.

Just spread the extract on a shallow tray and wait. Distillation would also speed things and you would also recover the solvent, but I guess if you are ready to ignite your solvent, you are not interested in recovering it. So just spread it thin and WAIT!

Burning IPA with goods inside of it sounds like a great way to light yourself or belongings aflame and burn all useful sensitive compounds inside. Candles burn from 800*C to 1200*C approximately. Now think about an alcohol flame. Apparently the heat at the surface of a burning alcohol solution is about 260*C (ref: http://wiki.answers.com/...mperature_flame_alcohol) the flame being estimated to about 1100*C.

Do as others have suggested or invest in a rotary evaporator.