I think once I get out of the early game a large number of my bro losses are to possessed fallen heroes. Even very late game bros with good gear will die if a 2h fallen hero hits twice. It is probably due to a bit of psychological bias opn the player part-against chosen or big orc camps you are at your sharpest but one turn of complacency in a necromancer camp can lose a bro in an otherwise easy fight.
I have over 3k hours played and when I saw this video I was hesitant to agree with it, but honestly your list is very spot on. I think the only thing I would change on your list is direwolves to be bumped up to anytime. For some reason I just don't run into many direwolves in my playthroughs as much as I did before the blazing deserts dlc, and because of that, I have trouble making the additional fur padding. I had one run recently with 2 full rows of the unhold fur but no pelts from direwolves to make them :/ So other than that, yeah I'd put direwolves right alongside hyenas. They're a fight you don't want to take before raider gear, but once you get raider gear (so day 15-20+) I will drop whatever I'm doing to kill direwolves now.
Quite sure :) Check out FeedingFriendly's 19-day Monolith Run. The only thing that would break the "infinite XP gain" is the Necromancer fleeing. But usually, 1-2 turns after fleeing, he rallies and the cycle continues.
You know, I did that at the beginning too, but I found dogs to be much better and economical way to deal with alps. They almost never miss them, they provide vision at night, take hits (2), and the reshuffle can save a hurt brother or lead you to easy kills. They're great!
Anti alp tactics early game. High hp bro at edges with nets and clubs. Mid game and later, nimble bro with pole mace. Take very little hp damage and concussion is very economical.