Depends on what outcome you want. The same skills that affect player HP affect NPC HP, so you can allocate to any of those for HP boosts. If you just want your brawler to hit harder, you want Strength. If you want him to take less damage, Vigor is the way to go.
Huh? I said that they didn't use the Unarmed Combat skill, because said skill USED TO BE Throw, and was changed. There is no "throw" skill, and you will not find any combination of skills listed for throwing things on the Rules pages, because no skills have been determined for that yet.
"May the Grace of Ara go with you, and His Vengeance be wrought upon your enemies."