1. IMHO, no.
2. Can't tell you specifically....but Mark, he's asking about the AEBL laser, not the AS Laser.
The steel in the HH is very nice and takes a great edge. Both can take a very nice edge. Between the two, which takes a better....I can't say with certainty.
3. Can't help much with availability.
4. A suji is meant as a slicer. Theoretically, it would have less wedging than a gyuto.....they're typically ground thinner, and they have a narrower profile = less wedging.