Ok lot of posts to reply to:
1. A1 merc
A1 mercs are nice but they are pain to keep alive on a non-summoner build, that's why I opted for not using one. I have no doubts they are good in earlier acts, all mercs are quite op to be honest. Also A1 feels lot better if you can specifically build around them, give them nephalem spirit for example. But I doubt you can make a1 merc just run with you in duncraig, and not die (a5 can easily do that).
2. Wolfsangel runewords (shaad axe)
It is good runeword you get about as high damage as good craft (250 dmg added but runeword can get over 200% ewd that makes up for extra damage).
Why is it not included: shaad is rarest toraja rune, expensive and rare. If you wanted to replace runemaster with it, it can't match, runemaster gives you up to 20% defense per rune, this gives 4. And on top of that you lose 5 runes from fact it is RW axe, so 1 rune in weapon instead of 6. In other words if you did that your defense would drop significantly. Neph spirit as well, not that good if you don't stack bunch of pierce all gear, which is typically rare su, xis runewords and such. None are cheap options.
I was thinking, just putting that axe on runemaster barb would probably result in roughly same defense because of 5 runes loss. Wouldn't be bad for aoe clear since that eartquake proc.
3. AH and Baelfire oskills & 2h barb set
Oskills you can see in video, I'm showing there are crafted helms with them. I also list them in 1st post in misc items section. You don't even need to craft it, you could keep creating blue items, if failed, renewal them to white, and repeat. But crafting is just faster.
As for barb set. It isn't bad, especially coming from cheap gear we are using in this guide. But reason is the same as in previous point, full set it hard to find, thats lot of rng. This set isn't that great overall, woulnd't be on list of "gg gear", but yes it is better than TU.
For tips on 125 ubers, you have video how I beat them with worse gear than 2h set, so its something to compare to.
For the RMB stance, there is that little checkbox in d2stats that "Continue attacking when monster dies under cursor" that helps a bit. But otherwise you just have to deal with the inconvenience.
4. Upgraded AHK script
Nice, I know you can add bunch of tweaks like that, didn't find need, trying keep things simple. Note you can use similar trick to cast screaming eagle throwing skill, while scripts switches off bear stance. It is useful in laz fight.
5. Strength requirement
Was mentioned many times. Runes (ko = 5% str), MO = +5 str per mo for armors, so +25 str per item). Charms (25 stats akarat, creature of flame, % stats tal rasha and so on). You can just stay on t3 labrys until you get there.
Resists: mo 3% all res per armor, 7% per specific res for rings/amulet (can have 35% all res for each ring and amulet). Runes for 20 specific res each.
You don't need to be using these runewords that early on, if it helps you keep using uniques until you get more charms. There is bunch of charms that also add all resists.