Some questions about soloing older expansion boss fights

[Gadoschi]

Hello, fellow Felsong players,

Over the past few days I have found myself unable to complete certain fights in dungeons and raids in which I went either for transmog gear or for mounts, so I decided to lay it all out here, NOT to report bugs (because I know this isn't the place or the way to do it), but to ask whether anyone else has had better success completing them. If so, I would very much like to read your explanation on how you do/did it.

I will go over bosses in the order in which I remember them, so don't add any specific meaning to it.

1. Illidan Stormrage (Black Temple) - this one might actually work, but it bugged out at 1 hpfor me; I believe it has something to do with specific phase transition required to complete the encounter; therefore, even though it seems to bug when you just mindlessly 1 shot it, I cannot confirm this as a bug; please comment if you have any useful information,
2. Kalecgos and Sathrovarr (Sunwell Plateau) - you cannot complete the encounter unless you enter the portal and defeat Sathrovarr, and if you do that, Kalecgos resets outside; this might, however, be resolvable by bringing another player to keep the boss busy in the other realm long enough for you to kill the one in the other realm; please comment if you have any useful information,
3. Yogg Saron (Ulduar) - I was told you need at least two players to do this fight, and I did just that; I used the portal to experience visions while my partner stayed up to keep the boss and the adds busy; however, after opening the brain room, I found myself being unable to land a single hit on the Brain of Yogg Saron because of a "target not in line of sight" bug; the bug persisted throughout the encounter and through all 3 different visions, so it's not just a one time thing; now, my partner managed to land some damage on the brain downstairs from the surface somehow, but we were unable to replicate this and we wiped due to enrage; I tried doing the same encounter by myself a day earlier and it proved impossible due to near permanent stun by the tentacles from the surface with the plague debuff; again, please share if you have any helpful information,
4. Al'Akir (Throne of the Four Winds) - now, in this raid I didn't even make it past the entrance since I cannot get any of the winds I tested to carry me anywhere where I can actually land, and I ended up floating endlessly between textures every time,
5. Zul'Aman Timed Event - it appears this one isn't even scripted, so it's impossible to obtain the mount via regular means (completing the event); not much to add here (except, of course, to correct me if I'm mistaken),
6. Midnight (Old Karazhan) - no loot dropped from these bosses; I wonder if it's a one time thing, whether I did the fight too quickly or is it just the way it is right now, and, finally
7. Spine of Deathwing (Dragon Soul) - I tried to have the Amalgamation do the Nuclear Blast in the middle, on the left and on the right near the tendents, and it would always say that the Blast didn't occur close enough to pop it; I would be delighted to hear your insight on how to do this.

Once again, this is not a bug report. I just want to hear how you guys do these fights or manage to loot the ones that don't seem to drop loot for me, so I can do it as well.

Thanks in advance,

Gadoschi