From testing so far, what i have noticed, 7k haste is doable without using FoF or Chi wave, you can dump most of the energy if you make the right decisions, the problem i have is when you want to use EB you cap almost immidately, the energy flow is jus too fast most of the time.
on terms of mastery, im finding that after the nerf is so hard to maintain high dps on fights, im pooling stacks past 10 most of the time to aline them with my trinkets for maxium output, aslong as you dont go over 20 its fine, but even doing that its not alot of dps, ive noticed ive lost around 10k in total to now from before 5.1 (i used to be top 10 on WoL everything 10 man hc).
I have tried gemming both agility and haste, i can say agility is not the way to go from testing, the damage on average was lower than with a high haste build, though i do think 7k haste is too much, i wouldnt worry about using FoF at all, since the same problems arise, if you have to move, its a dps loss, theres also the fact in them 3 secs you gain far too much energy, not saying you cant manage it but if you get a cb proc its really hard to deal with. Chi wave im not finding to be that useful, im using it more towards like we used to do/still do with flying serpent kick on low energy. otherwise im jus not using it, i can get probably 1-2 less EBs off than max atm with how fights are going, its really hard to use it off the start, well even 30 secs in to get maxium use out of it.
on terms of Accession vs Power strikes, as far as we know Accession gives more chi per min than powerstrikes, so i will not try changing that, since overall we would benefit from a high haste for a loss of chi, which seems like we would be wasting stats.
Overall going to try around about 6k haste build, using FoF like i used to, ie low energy situation with more than 3 secs on tiger palm and 5-6 secs on rsk cd, try and get back to using EB on cd, but still delaying 10 - 15 secs at the start of the fight. I do think getting used to a mastery build is definately the way to go after haste though, we may be low now, but im pretty damn sure soon as our item level increases we'll become top dps again jus with how the scaling of that sort of damage increase will work.
On other things, that 10% nerf i feel was too early, sure our dps was high before it, but they should of atleast gave us a bit of time to gear up before changing it so like every other dps doesnt roflstomp us on meters
(sorry for if this is hard to read, Dyslexic ><)