What can be used as a small container for paint

Do not prime the drywall before it is taped and sanded. Do all your drywall work first, then apply your textured coating. Normally there is no reason to prime the new drywall or joints before putting on a compound based textured top coat. If you intend to use a textured paint instead of a compound based texture, then you would prime the entire surface with a PVA drywall sealer/primer before applying any paint coat. Assuming the texture is compound based, then let it dry completely and prime this with PVA sealer/primer before painting. Do not use a regular heavy based primer or paint/primer product on your texture. Use PVA. The reason is that PVA is very light and dries extremely fast and if applied properly won't re-hydrate or saturate you texture causing possible damage. Once the PVA is cured, (usually just an hour or so) you can paint over it with regular latex paint without fear of texture falling off.

I believe that this will end up in the wood working SE, but it should be noted that furniture wax is really wax like from a candle; it could be beeswax or petrol (it's not like floor wax which is definitely not wax). Wax is "non-polar". Wax can be cleaned with naptha or paint thinner, which are also non-polar molecules (like dissolves like), but that might make cause the wax to penetrate more deeply into the wood. The same might be true with heating (as Ed Beal suggested) but I wouldn't dare use a heater (or even a hair dryer) near acetone (boom).

The Zinzer BIN shellac is true shellac (meaning it comes from the insect) and it is alcohol (semi-polar) soluble. Wax will not readily dissolve (well) in alcohol and shellac will not dissolve in anything but alcohol (not water nor naptha). So you need to use a non polar solvent, something like naptha to remove wax, and then you will need to remove the naptha or paint thinner from the wood. Acetone mixes with both nonpolar and polar subtances. Acetone can dissolve a naptha-wax mix, and it will dry more quickly than naptha, and acetone and ethanol (shellac base) are miscible.

And acetone can help (a little) with allowing ethanol and naptha to mix (but not very much). After stripping the furniture with a non polar solvent, you should use acetone to rinse out the non polar solvent, then let it dry (kiln dried would be best). Another non-polar solvent that might help would be diethyl ether, but that's even more flammable than acetone.

Prepping the wood for asorbing ethanol: I would consider (as a last step) applying/cleaning the wood with a 50/50 water alcohol mix (with a rag) a few times, and then letting the wood dry. After a few treatments it might help prepare the grain for absorbing the alcohol/shellac. Water will probably discolor the surface of the pine, so you should be prepared to sand (lightly) before applying the shellac.