Very very slight offset question..

XLR8SN

Springs only is not going to create enough negative camber....stay with the +22 fronts I would say. +17 rubs already on a .8" spring only drop.

Unless you change out front the suspension for camber adjustable arms...+12 is going to rub I am pretty sure. I am going off of a 245/40 front. You can "make" it fit with a 235/40 or a 225/45 19...but then you are probably going to have some serious "pushing" issues. Granted you can make it fit, (flaring the fenders, moving the fender clips, stretching tires, etc...) but if you are going to just install and drive...then I would say +22.

Brake clearance question cant be answered with the information you provided. It all depends on the spoke design and the clearances it was designed for. Ask the vendor or the wheel company for the answer. Cause if you still really want "that" particular rim and it needs a spacer to clear the brakes, then you are going to have to calculate the offset to accommodate the needed spacer width to the total offset it will give you combined. Keep in mind though that anything more than +5mm in a spacer will probably need longer wheel studs as well, unless you use the KICS/Ichiba version with built in stud extenders.