If you were able to get the spring cups on with the 1/8" gap, then you are good. As long as the bolt holes line up, then it is there. Once you get it on the road & it gets a little water in there, it will "rust tight" them suckers for ya
. The 7* bushings should be fine for a 3.5" lift. Typically, those are reserved for any lift over 3", such as 4" or 5", but they still work with the 3.5". The bowing of your coils isn't a problem, they will do that until you get the weight of the vehicle back on it, see the pix of mine, which are 5.5" coils. As for the pinion angle, it is hard to tell, but like Bob said, you don't necessarily want them pointing directly at the U-joints, which you might not be able to tell until you get that weight on it.
One last thing, and this is my opinion only, but I would rather go with a track bar riser on the axle than the drop bracket on the frame because it causes more stress than needed. The drop bracket puts torque on the frame and can (this is just a possibility, not saying it will) tear the frame. The riser is on the axle tube and has less torque on it and can actually align the track bar better (see the last picture). As for getting that bar re-connected, the easiest way that I found was to put it on as the very last thing, and this is for using both the riser or drop bracket. Put the vehicle back on the ground & get a buddy to rock the front end for you. Don't put the shocks on it yet, but rock that thing back and forth & it will work it's way into place. A do it yourself is the come along method like BB mentioned.