Why don't you make guides for lvl 10,20,30 and so on.
I only bothered watching the first video so here goes: saying that a lot of mobs have a lot of cc doesn't help random people. Your guide would be a lot more helpfull if you actually said, prioritise shamans since they grip you away, and so on. Also at the great balls of fire part (0:50in your clip) you have a little platform where it's safe to stand, so aim to run there (if people die near it they can be rezed easily)
The veterans at the sacrifice part can be knocked back, crippled immobilised etc etc to help you kill them before they get to the bad side.
Constantly tossing stones isn't worth it if you want the chest with extra loot, it's better to zerg veterans down and then pick up stones and toss them.
Simply strafing is enough to avoid most of the targeted aoe, the big charged aoe he does is a good example aswell.
Also note that when he is shielded you can keep stacking conditions so if you have condition dps keep them on the boss.
No killing totems isn't worth it.
Next boss, you can avoid most of it's dmg (agony included) by left right strafing (shortly but constantly) so the projectiles miss.
Taking down the lava grubs isn't a priority it's more important to zerg down the shield first.
The villagers come into play from lvl 1, when shielded the boss tries to get to them to sacrifice them and restore health.