Having completed tribunal/bloodmoon at 530 HP on a theif charecter at difficulty + 75 i can tell you that 774 HP is completley unessecery with a absorb health sword. and a enchanted constant effect restorehealth ring. the fact that i had to up the difficulty to +75 for a group of 5-7 enimes to even phase me says as much i think. The only charecter that really benifts from extreamly high HP's is a werewolf since their HP is 2x normal, and not being able to heal yourself you need it. Starting out and untill you can get absorb health or CE Restore Health, healing potions work fine, their fairly cheap at 35-175 a pop and extreamly effective restoring 50-200 within 5-10 seconds. aside from that potions stack as well so you can take down something you normaly couldent if youve got the gold to spend on quality/exclusive healing potions. Lastly if you use ranged attacks in the early game, like fireballs and bows you dont need as much starting HP becuase nothing will get close to you if you do it right. Mages can also use absorb health or strong oneshot custom spells and skeleton minions early on to compensate for their low HP, theif based charecters can compensate by using stealth critical hits, ranged weapons and jink blades. My lvl 1 mage had a absorb health 11-52 on touch spell right off the get go, only cost about 500gold i think, you can buy it in sadrith mora, and what do you know you can get there from seyda neen for about 45gold using the stiltstrider and mages guild transport. ;)