The DM we had 30 years ago had a deal where you got at least 70% of your hit points at levelup and you got a roll. If it was better, you got to keep it. I always used it. The twister is so unkind in that department.
This issue could be resolved by simply adding a set number of points, or a set minimum (d10 becomes 6 + d4), at each level up. When did D&D stop basing exp point awards for monsters, at least paritally, on the creature's rolled number of hit points? I'd max npc hit points all the time if ToEE were that way.
Maxhp for characters makes the game easier. I agree that the RNG gives you some bad runs. Oddly enough so do dice. But I have no problem with maxhp if the monsters get it too (and no extra XP).
I've always prefered systems where hp change based on stats rather than level. Doesn't matter how good a fighter is, a sword to the torso is bad news and being outnumbered 2 or 3 to 1 is a serious threat no matter the opponents. Characters having 20 and 30 times the hp of other people and needing to be hit dozens of times is way too abstract.
"Heal enables you to channel positive energy into a creature to wipe away injury and afflictions. It immediately ends any and all of the following adverse conditions affecting the Target: ability damage, blinded, confused, dazed, dazzled, deafened, diseased, exhausted, fatigued, feebleminded, insanity, nauseated, sickened, stunned, and poisoned. It also cures 10 hit points of damage per level of the caster, to a maximum of 150 points at 15th level. " It doesn't say magical diseases are specifically unaffected, so I'd assume that means all diseases would be cured via heal.