I never had problems with pins been in a straight line. All manufactured bows are done that way. I use a 7dg. pad angle. My reasoning is it puts less stress on the limbs because I'm building wood bows with minimum reflex, anymore extreme angles would mean more reflex in the tips, that places more stress. The issue I have is aligning the bolt hole and pin hole because I don't have a drill press. This time I'll make a proper jig in the hopes of aligning everything up.
I see no reason for having offset pins, other than maybe having more stability between the riser and limbs. BobLee bows have 2 pins.