I use a Wallytractor to do the basic alignment and I use a 10x magnifier to see the markings. The Wally Tractor is not the easiest tool to use, but it gives you more ways to confirm your alignment is good than other protractors and it is the best thing to use for my Vector arm which is a little bit hard to locate the precise center of the pivot. I also have a SmarTractor (donated to my local dealer) which is far easier to use and I highly recommend it where the pivot point is easy to find.
I use a mirror of the right thickness and the magnifier to confirm proper optical azimuth setting.
VTA/SRA I set by first establishing thar the arm is parallel to the record surface (a ruled index card set just behind the arm makes this easy. From there, I just experiment by listening. If the pivot is raised too high, the sound is thin and sibilant, too low and it sounds dull.
I have a USB microscope, but I never use it for alignment because it is a pretty fussy thing to set up and aim properly.