Well, first of all, a big
THANK YOU for doing this to yourself at all!
Been there, done that.
1
) What constitutes an acceptable model?
Well, one whose parts fit together (just as Blaar said).
2) What is an appropriate scale, or size?
Scale mostly depends on the size of the Original.
Size of the model iŽd personally say no smaller than half my keyboard or 1:1 (whatever is smaller)
and for the big end...as long as you can find a place for it, its not oversized
.
I build planes and vehicles in 1:33. My biggest ones now are DC-3 and Ju-52, but my biggest one ever was a DC-9
(sadly , it literally crashed...).
3) What file type is most acceptable?
One with as low data compression as possible.
PDF with Vector Data; PNG; Tiff, low-compression JPG and well textured prepakura are my favorites.
I
HATE artifacts clogging up the texture!
4) What File size is appropriate?
As storage technology and download speeds are improving, iŽd say one should be able to open and edit the files
without crashing an average computer system (which is improving as well, so this might no really be helpfull...)
5) How detailed should directions be?
I find step-by-step instructions showing the more complex steps with still pictures should cover everything, including eventual language barriers.
And finally:
Just remember, even if you deliver The WorldŽs Most Perfect Whatever Of All Times, there will still be someone who has the need to complain about something.
Must be some kind of law of nature.
I hope that helps...