remember line out is different to a D.I so make sure the xlr output says D.I and not line out. just looked at the manual and the balanced lineout has a level pot so that should be fine. i say this because my sunn 300t that i had has an XLR line out and i thought it was the same as a D.I but it isn't. the signal coming out was hot as hell.
also distortion pedals shouldn't go in the fx loop ever really. that's just for delays, chorus etc