I pronounce it Pass-Kal (fairly even syllable split, a flat A in pass and longer A in Cal). The French way I guess! Apparently it’s much more popular in the feminine form for girls (Pascale) so there might be some annoying questions for him as he grows up. It’s pretty cool. Don’t adore it but it would definitely work, suits the set, and like that there’s the family connection! Pal, Paz, Pac or Cal all cute nn’s.
Would Blaise be an option? Maybe not, might get Blaze.
(Still hoping for Florian - Florian Pascal would be fab 
)