My rear sight is off 20 clicks left to get zero. It just looks goofie. I tried partly drifting the out the taper pins on the front sight then rotate the front sight base on the barrel using a maple block. It did not move.

For now, I am going to assume the barrel is not crooked and the crown is good, it is a brand new rifle.

Should I be looking at the barrel being installed a few degrees off or the sight being canted? Both? Am I being too picky?

For arguments sake, if I was going to rotate the front sight on the barrel, how best to do that? Drift the pins out. Rosin and maple blocks to hold the barrel? Then a good wallop with a maple block and hammer? Should I expect to heat it first?

Sounds like your barrel is indexed just slightly off. It is almost impossible to move a front sight that is held in with the taper pins without some very tricky machining work. The pins return it to position. Very easy to loosen the barrel nut and index the barrel a few degrees. The pin on the barrel extension that indexes into the upper receiver has some slop in it

The pins are not tapered. They appear to be 1/8" music wire or drill rod. They do bring it back to crooked if you take them out and "straighten" the front.

I guess I need to buy a wrench and upper clamp block. Wish I had spent more and gotten better quality. I would have saved some money.

Remove the taper pins & front sight.
Drill & tap the sight on both sides & install set screws to push the front sight with rear sight set at zero/mechanical center.
A spot face in the Bbl under the set screws ensures positive movement.
A third set screw at 6o'clock position locks the sight in location.

The option has been used on NM AR rifles for the past 20yrs!

I use 8-32 set screws instead of pins in an un-drillled A2 tower

one between the swivel pivot and a long one through the bayonet lug

spot face one at a time through the holes after your done sighting in

Sounds like the guy who built it didn't make sure the barrel was index properly.

The proper way is to re index it.

There's a reason that front sights are pinned so they don't come loose.