I wouldn't really worry about expertise as much unless you are having threat problems. Dropping below 26 is fine and you're still at 29. I do think your armor is a tad on the low side, but not a huge deal. I would suggest using clutch of fortitude (or even better, H-band of the twin valks) over harbinger's bone band, the armor on clutch is just too good. I'd change the gem in your help to 10def/15stam since survivability > threat, and also change the gem in your neck to 30 stam. Other than that everything looks hunky dory.