to add to this - i was doing LFR on work laptop at the office occasionally alt-tabbing to get work done.. So it's *possible* that I missed some stuff..
no clue about twilight sappers
yes for both purple swirls
for bloods - when you kill them, no matter where you killed them, they would drop something on the ground. tank who has the amalgamation thing would just run it over the blobs on the ground. so you could see one go from 0 stacks to 8 (or whatever) right away. no stuns by tentacles
madness - there was this big tentacle thing in the back you had to burn, then kill bolt, then kill off that tentacle thing, then aoe adds (all the same), then finish of deathwing limb. Order was platform you start on, left, far left, far right i think. maybe it was far left second, i forget.
For small tentacles cleave dmg was easy enough - there were a few raiders who got on them right away and they were burned without anyone even noticing them.