Advanced questions for Frost Machinegun dps

[FireWater 0]

The advice for frost dks on this site right now seems very... oversimplified. With so much different gear, with different legendary combinations things can get rather variable, so I had a few thoughts and questions. 

Firstly, base 'rotation'. Recommended talents tend to go:  Runic Attenuation and Obliteration for single target, or Frostscythe and Glacial advance for the aoe true 'machinegun build'. Single target with obliterate is simple enough, but using machinegun build during periods of single target dps, all they have is a base priority list that seems lacking. 

They recommend: 
Frost fever up>Glacial Advance>Remorseless Winter>Frostscythe>Frost Strike

And that's really all it says. I've been sticking with the same talents even in single target, and I've been making due with the following:
Frost Fever up

Frost strike to keep Icy Talons from dropping (typically once every 2-3 global cooldowns) or if your RP is almost capped.

Frostscythe with KM proc

Howling blast with Rime proc

Glacial advance and Remorseless Winter when available

Obliterate for rune dump and rime procs

 

Done properly, and with normal luck on procs (and decent haste), you should be able to keep Icy Talons at near 100% uptime. 

Beyond that, the stats it advises amounts to soft crit and haste caps, then Versatility > Mastery. But a spec using lots of RW, GA, and big Frostscythe crits makes me wonder if more mastery wouldn't be better. Especially if you get  the legendary bracers (Toravon's whiteout bindings) which give an extra 15% frost damage during PoF.

With the same legendary in mind, is it worth using Frostscythe on single targets during PoF?

And if you have the bracers AND the ring that gives 2x charges of Empower Rune Weapon, how does dps compare for Breath of Sindragosa build? I can imagine amazing burst dps every 2 minutes, but would that make up for the lack of avalache and glacial advance?

[Drtain 74]

well the main thing is the GA Frost Scythe build isn't really every used, like ever in raiding. It's not covering m+ but yeah I mean it's pretty 'basic' of just going to Obliteration rotation completely cutting Frost scythe of the rotation as well as GA unless you have the bracers then GA during pillar of frost is used. Keeping up icytalons of course is ideal.