You should feel comfortable skating balanced over one foot.
Most boot fitters offset the blade mount to one side to achieve this.
If taken too far, this makes your foot very sore, and results in unequal loads
on the sides of your bone (creating possible bending and fracture) and can create
overuse injuries of your muscles and ligaments. It works well if the offset is
not too large.
Incorrect skating technique can also create imbalance, and generally will for beginners, who usually lean to the inside - ask your coach. This is because most beginners are afraid to put weight on the outside of their blades, for fear of falling over. So can assymetric blade edge sharpening.
Most people's bones, mucles and ligaments are organized for weight support
to go through a line from about the middle of the heel, to the midpoint between the
big and second toes. That is the line along which blades should usually be mounted.
The mounting plate should usually be mounted to be centered forward and back in
relationship to the foot.
Generally speaking if that does not create balance, it is because of unequal pressure on the insole, or on the sides of the boot - discussed earlier.