I meant to make a quick post about this hrs ago...oops.
There are low boards 60.1% of the time, so boards without a low will occur 39.9% of the time. The scooping %age will be technically player dependent since it depends on folding. In a no fold'em scenario, the scoop happens roughly 40.64% via simulation 10-handed. Using pql:
select count(scoops(p1) or scoops(p2) or scoops(p3) or scoops(p4) or scoops(p5) or scoops(p6) or scoops(p6) or scoops(p7) or scoops(p8) or scoops(p9) or scoops(p10))
from game="omaha8", p1='****', p2='****', p3='****', p4='****', p5='****', p6='****', p7='****', p8='****', p9='****', p10='****'
As for at least one player getting A2, an approximation is 1- (1-0.06396)^10 = 48.4% based upon math linked below. However, dealt hands among individuals are not independent, so this answer isn't exact.