The rear sight has a windage adjustment screw on it, there should be no need to move the front sight unless the rear sight won't adjust enough to compensate for the degree of deflection...
As for the amount of shots between wiping the barrel, that depends on the lube, powder and loads you are using...
FFFg Powder burns cleaner than FFg, but gives higher pressures...
Heavier loads (more powder) produces more fouling than lighter loads, more carbon to deal with...
Lubes range in all types of liquids and solids, many swear by Natural Lube 1000, some like Moose Milk, others use homemade concoctions...
Trial and error will let you know, household items like Crisco (in the can) and Olive Oil also work...
Experimenting is half the fun, and you get to shoot more in doing so...
If you do need to move the front sight, it is dove tailed in the barrel, use a brass drift and a small hammer to tap the sight (by the base, not the blade) in the direction you want to move it...
Make sure the muzzleloader is unloaded before doing this, standing behind the barrel, not in front of it...