The last boss:
Personally I switched from prydaz on the last boss because it fucked me over twice. Probably can work around it but it just turned out to be an unnecessary hustle for me so I dropped it. You don't need to worry about the npc's too much so just concentrate on managing your hp. What turned out to be quite important is dmg. So I do recommend waiting on your second drums. I usually had 4 mins debuff when I got to the top so I only had to wait a minute or two to have it on the bossfight. Probably I was way too occupied with the boss' jump and Ignite Soul so I ended up doing not enough I guess because even with drums and pot the whole room was used up by the time he got to around 5%, and died. The npc's finished it barely.
I used prydaz (switch to tearstone for the last boss basically just for the stats and because I dont have anything better but you dont really need any healing boost anyway) and aman thul which I think had really good synergy with abundance. ToL just makes the harder healing parts easier even though some people still used cultivation, so it isn't mandatory if you don't want to. I also went with moment of clarity. I'm not sure what use flourish has if you run with shoulders and abundance (you have extended hots anyway and no CW?) but I could be wrong here.
So my best advice is:
Pot every chance you get and put in as much dmg as you can, especially the last boss.
The healing aspect of it is pretty much just blowing cds in stage 1 on the last wave and stage 5. TQ/ToL/EoG these and its fine.
Interrupt with typhoon. I usually used it on enraged mages because if granny gets an arcane blast and a deadeye shot she's done. At the Mage-Warrior-Warrior wave you can triple interrupt an enraged mage and two knife dances. Definitely go with typhoon in my opinion.
Be careful with dotting the eyes, you have time to just kill them one by one and be safe.