Your query about alignment.
You need to align the belt by locating the pulley on the motor shaft, to avoid wear.
My Chinese Mill/Drill shredded the primary belt within six months, because the motor pulley was out of position.
Having realigned it, using a straight edge across the pulleys, the replacement is still going strong some 16 years later. The secondary belt is still the original!
If you bush the new pulley, and want to be certain, you can drill and tap the pulley/bush on the joint line and Loctite in a grubscrew as a dutch key.
Howard