Haven't finished everything, but I enjoyed what I read. I got back into D2 soloplay and am still most fascinated by 1.07 even with all its quirks and bugs. Hoping you great success on gaining the guardian title.
I'd give some heed to Joey's warning about hell baal though. It sounds insane, but hell baal is pretty nuts in 1.07. His mana burning flame does magical damage so it can't be reduced by elemental resistance. There is no % magical reduction and flat magic reduction doesn't do enough since the attack counts internally as a single missile attack (if I recalled this correctly) and not as a continuous attack. The best advice I heard was just to avoid the attack altogether by using the pillars as shields. In terms of numbers, I believe his attack does around 1500-2200 (I've heard both numbers but think it was closer to 1.5k for single attack) damage if it crits. I've heard a 3k number quoted as well but I think that's only if he and his clone both hit you at the same time and they both crit, which is pretty unlikely. I don't think I've ever seen that happen or if it did, I blocked it out from my memory. So it's pretty bad, but you can deal with that in SC since Baal won't use it in every fight and won't crit you with it every time. In HC, you don't have that luxury since if that yellow flame pops off at melee range, you basically have to eat between 750-1500 of unblockable damage. You basically either have to have the HP to eat it or you lose your character. Of course if he never uses that attack, then its a pretty straight forward kill, probably easier than killing one of the multi-shot, LE etc. boss packs.
Edit: Tried to look up some info and found one of fruit's post in 2018, who I think is one of the foremost experts in old D2 mechanics. Trust his words more than my memory:
Baal's beam is a single missile that deals 512-544 magic damage on Hell. But since your Magic Resist is -100 there (caused by the difficulty penalty), it will deal 1024-1088 magic damage. Like anything else, this missile can crit for 2048-2176.
MDR will reduce its damage, but since it is only one missile, MDR gets applied only once to this massive damage.
After MDR has been applied, ES will reduce the remainder of the damage (but not before the beam takes 50% of your current mana!).
The stuff about Laying of Hands and 4-frame hit recovery were all myths unfortunately, none of that will help you.
The conclusion.. Avoid that beam. 
Otherwise, your only options for protection, like pharphis and zemaj suggested, are high life, MDR, and ES.https://www.diabloii.net/forums/threads/1-07-news-info-and-gossip.575127/page-227This post was edited by downding on Oct 24 2021 10:29pm