A Dremel can be handy but hardly required. About the only thing I use mine for is to cut music wire and bob bolts to length, polish silver-solder joins and smooth openings in cowls. It's way too aggressive for balsa work. I have a blackpowder gunsmith friend who calls Dremels "the Quicker Bugger Upper" and says 30% of his business is fixing what folks have done to their guns with Dremels.

Way more important, to me, is a wide assortment of clamps. Get two dozen spring clothes pins and invert them. I also really like the House of Balsa rib jigs. Six of these and you can rip off a wing half with CA in 20 minutes (not including the pre& post sanding). A bunch of lead weights have proved invaluable in keeping the work in place (I use Titebond II as much as CA).

I sunk the bucks a while back and bought an end-grain balsa building board. This is a wonderful thing. Mins is 16" x 36" and I have built up to 1/4 scale size models on it. I have a roll of wax paper from a food-supply outlet that was 500 ft x 36" and is about half used up after 30 years (and having also double-wrapped numerous venison cuts for the freezer).