Anyway I'm breeding a Salamence and got one with good IVs except for 8 in HP. Is that horrendous? Should I raise it? How important is HP for DD Salamence?
Sub doesn't have priority, unless a Prankster 'mon uses that move. I'm assuming that Gallade got the Sub up first because either it invested in Speed or Salamence didn't invest in Speed at all.
Also, HP IVs don't really matter on sweepers like Salamence IMO.