Vee's pretty spot on with his thoughts.
You are so far beyond permadom with the build the way you have it you can make lots of changes and still keep yourself there.
One of the tricks I liked with characters that had kb was to use the FFs to supplement Hasten. You would be just about perma there and then you can concentrate on other goodies like Defense, health, regen what ever you want.
Personally, I'd dump stealth, invis., accro. and pick up the sleep (sneaky good in a few situations) and then get a touch of resistances (maybe charged armor and power sink) and try to pick up about 10% more defense. That would soft cap you (including the PB+Earthquake -tohit) and provide a lot of survivability so you can go much further without taking a rest.
The other thought might be to keep all your recharge so that you cap it for your Volcanic Gases. getting that up as often as possible sounds really nice. Not to mention power boosted Earthquake on command.
As it looks this build would probably perform really nicely. Maybe not solo a GM nice, but great at a lot of the gameplay available.