2. Kind of, but not really. What's nice about it is it's consistent, where as wood can vary a bit from piece to piece. This is nice if you're going for very specific weights, or want the extra predictability. Bamboo itself is a good material because of it's strength, though I've started doing mixed cores with bamboo on the back, maple on the belly with very nice results.
3. I recommend UL if you're going clear, especially with dark veneers. I use ULS for anything that doesn't have veneers under it, as I think the scrim adds a little bit of torsional stability. Haven't used ULS in a full limb, so not sure how much there is to the torsional stability argument. Going to try adding uniweft in my next one to help with torsional stability.