I just want to do a bit of brainstorming - I know this'll probably be a couple years down the road:
How can we make elves a playable fortress race and make them interesting?
Given what is already in place in the game, I think they don't really need any more professions, except for some kind of engineer to build tree forts. What I think they need may be a new racial ability with what professions they now have tied to them.
I propose:
[PLANT_MAGIC_HARVEST] This tag would specifically allow elves to harvest wood and fruit from plants without killing them, and to get wood without an axe. Should be significantly slower than the default "killing the plant" version. Furthermore, harvested wood comes already shaped to it's intended function: carpenters directly get their wooden chairs from existing trees instead of cutting wood, then taking the wood to a workshop to shape it.
[PLANT_MAGIC_GROWING] This tag would allow elves of a specific profession to take existing trees and alter their shape and size into something desirable. Elves wouldn't be able to morph tree trunks into completely contrived shapes - they should only be able to change trees in preconceived ways:
Trunks can be enlarged, hollowed out, and have stairs/ramps added. Trunks can also have points from which a limited amount of sap can be extracted for "water."
Branches can be turned into floors, stairs, and furniture.
Leaves can be turned into doors, grates, walls and fortifications.
In order to build, the wanted tile is "grown" from existing material and such growth pushes adjacent material away from the trunk. This means that it's possible to change the shape of existing rooms without destroying them, and that shape will change the shape of anything else that's farther away from the trunk than your tile addition/deletion. It also means that you can't suddenly add a leaf wall in the middle of your wood branch room if there are no other leafy tiles nearby.
This might also be a bit easier if trees were allowed to grow more than 2 Z-levels tall naturally.
Ideas?