Front suspension suggestions for better tracking
Looks like you have the usual good guys helpin you out, but my advice would be to find another alignment shop. I don't care how good they "seem" to be, if they cannot get any more than 3.5 degrees positive caster and you HAVE aftermarket adjustable control arms like you say, then they're doin it wrong.
Whether or not that's your wandering issue, I don't know. I can tell you the two biggest contributors to wandering is not enough caster and not enough toe, with incorrect camber setting coming in a close third. As long as camber is "close", with radial tires, it should not have a huge effect because the radial tires tread footprint stays on the road for a much longer radius through camber travel than the old bias ply tires did. Now, as for handling, camber differences can be pretty big. Refer to the skosh chart to see what type of driving you do and match that up with the figures on the chart.