I don't know how much altering jackrats will really help. The issue is mostly with DF as a whole. You could run your meet industry on mastiffs, unicorns, or ogres if you really needed too, it just takes longer to get started. Once you get a high enough breeding population, the mechanics of reproduction start getting a bit extreme. Jackrats just hit that point really quickly.
One thing that would be great (and it would probably require a df-hack script to make it work) would be to randomize pregnancy times for animals entering the map. Right now, I find that the first year as kobolds is pretty tough, as one has to wait until all of your jackrats have children almost at the same time in the middle of the first winter.
Removing one of the drying steps from pottery would help reduce the action-economy cost down to that of glass.
I think that clay bricks (which can just be sun-dried in reality) shouldn't require a firing step to make. Drying them should be enough to make them usable. Possibly baking them into stoneware could increase their value and make them lighter. Alternatively (and this is kind of weird) you could use the pottery to make 'wet clay bricks' which count as -seeds-. Planting the brick seeds would represent your citizens leaving them outside to dry. The resulting 'plants' could get processed into working bricks at the Pottery. This might interact weirdly with the existing farming mechanics though, in that more efficient farmers would make more bricks...
Is anyone else unable to make normal planks? I can make polished wood into planks, but not normal wood.