got a whole nice reply typed up , only to hit submit and my laptop battery died , so now im on my eee ... here goes...
1: google quartersawn , and it will show you how to identify quarter and rift sawn.
2: long string should be long enough to get onto your tillering stick or tree. once you get the limbs bending an even amount (usually 10inches is what i see) , you put the short string on , just tied tight , not braced. then tiller as you were. ive seen all kinds of material for tiller strings. everything from regular bowstring material , to paracord. i used some cheap walmart knockoff paracord in the camping section. its actually a cotton daisy chain , with a poly shell. it holds up pretty good.
3:someone else will have to answer this , but from what i have seen , different backings go on at different times.
4:i havent gotten this far yet...
5: this is dependent on what your needs are. most people say that whatever your grip area is , add half of that length onto each end.
6: this is all dependent on what you want as well. they say long bows are more forgiving of tillering error , but from what i have seen , it all depends on what you want to tiller.
7: this is in a lot of build alongs , if a piece is twice as wide , i believe its 2x stronger , if its twice as thick , is 8x as strong.
hope it helps a little ,im still new , but the build alongs are priceless.
-hov