Greetings PartagasX, I am also swimming in the pool of 1991 Topps amazement.
For #1; Yes.
FYI - I purchased (2) sealed 1991 Topps Sets - white box versions. These two boxes have the same style of printing, but have noticeable differences.
Box. (A) The blue printing is blurrier, the blue color screen print is noticeably offset, the tape has "Topps 40 Years" logos silhuetted on it and most interestingly contains a complete set of non-dark logo, non-glow back cards.
Box. (B) The blue printing is clear, the yellow color screen print is a little offset, the tape is clear with no logo silhuetted, and contains a complete set of non-dark logo, GLOW back cards.
I cross my fingers that I can find reasonably priced dark logo uncut sheets or sealed sets of each for the completness factor. I am hand collating sets right now.
For #2.
- Yes on the glow and non-glow version dark backs. For statistics -> I have ~16k 1991 Topps Baseball from various packaging and regions around the country. About 10% are glow dark logo backs, and about 1/2% are non-glow dark logo backs. I don't have the volume of the variety of packaging to say that trends are accurate, but its a start.
#3 your variations should exist.
#4 Nice on Desert Storm, I only have one non-fake version and it is non-dark logo, non-glow.
#5 My (1) Micro Set has variation in the back that seems consistent with glow/non-glow. I have a second micro on its way to see what it looks like.
#6a Tiffany Parrallel, a good sample of what the set is "supposed' to be.
#6b Topps Traded, Have the white stock factory set, and grey stock cello style plastic wrapper packs. Don't seem to glow for me either.
#7. Topps Debut, mine no glow either.
#8a. O-Pee-Chee has Glow backs too?
#8b. Bowman glow backs. Doesn't seem to be much posted on here about those.
My add on was the complete set oddity.
Have Fun!