All good points! In response:
1. Quite a detailed new game customisation screen is planned, but I think I'll add a simple one in the meantime for options like this, to specify an amount of trees and that kind of thing, hopefully.
2. I'm planning to add a screen for an overview of your dwarves as the next feature, and it'd be good to have something similar for resources too.
3. This'll be open to modding when that comes around - this is due to be the next major release except for the small features missed out of Alpha 1 like the settler management. For now, holding shift will let you pan around faster.
4. It might be a little later on but there'll be a "roofing" view to let you see what is and isn't supported. A highlight when placing pillars is a good idea, I'll see if there's a way to get that in quickly.
5. The job prioritisation is based on professions first, then things like hauling water which don't usually require a profession (moving water into a cauldron for soup might be tied to cooking though). Following that, they'll work on whichever job is nearest based on the profession order. I'll be adding something to let the player manually prioritise certain jobs, and perhaps later a screen to manage the automatic prioritisation of types of jobs over other ones.