Aye, the glaze system is woefully unfinished. The main problem is that its a flat increase in value, so a novice glazer increases decoration value at the same quality as a legendary +99 glazer. However, if this was just ment to make earthenware water-tight, then why are we able to glaze statues and crafts? We can even glaze (some) stone-based items to increase their value! Stone statues don't exactly need to be made "water-tight" My point is that even if Toady half-assed the "glazing as a decoration" aspect, he still added it to the game. So just as we can add tin-glaze to statues, why can't we add wax polish to beds and tables? Also, isn't wood naturally water-permeable? I don't know about you guys, but if you've ever tried to pick up wet timber it is immensely heavier than when dry. The wood just soaks up the water, and presumably will leak the extra moisture out the other end. Its like those paper (which is a wood product...) cups you get at fast-food restaurants. They have a wax coating along the inside. Without this thin coating, the paper becomes soggy and the soda will begin dripping out the bottom. I'm pretty sure ancient coopers had to add some sort of polish or finish to the barrels (usually tar/pitch iirc) to keep them water-tight. Otherwise, the wood just soaks up the liquids which begin to drip through as the wood saturates. To surmise, just as earthenware needs to be glazed before holding liquids, wood would need to be treated/polished before doing the same. Since we would already add in the functionality of wood-polish, we might as well polish beds and tables to make them prettyful. Dwarf Fortress is already a game about meticulous and annoying supply problems, so whats the big deal?
To actually address the OP- I've long wanted an expansion of moodable skills. If we can make near-worthless "artifact" wooden puzzle-boxes, why not near worthless artifact wax bracelets! I'd personally like to see pottery added to this along with expanding the amount of items one can make with clay. We can make glass furniture and towers out of clay bricks, but clay tables and chairs are just silly? One thing you didn't think of is the addition of scents to waxes. Presumably we could also add fragrances to soaps, but this would be a great way of making your higher-end waxes. Naturally, nobles would prefer having lavender and rose scented candles while the peasants were stuck with plain old PEASANT candles. You could also use these scented waxes to polish wooden objects, so your nobles can go to sleep at night on top of their shiny orange-scented beds.