The forums seem to say that a lot but I prefer Stormwind by far.
Yep, that is exactly what I did when I was not sure if I could do a full clear 
You get way more coalescing now, too.
I just did mine to get to 80 percent, 8 minutes before the server went down; I hate when I put it off that long Yikes! It was still showing 77 here, so I got back in game to check for sure. Lols
You can still kill him. Just go in with your cool down ready and if you need you can popup a combat potion or drum.
I think it is mostly due to the Alleria fight being such a pain in the butt with all those AoE sanity attacks.