Yes. In adults, bowlegs are usually due to arthritis and can only be corrected surgicially. In children, there are nutritional and developmental defects that can sometimes be corrected with nutrition or bracing.
No. At the age of 26 only surgery will help.
No. Walking differently will not change the structure of your tibial bones.
No. Bow legs are due to bone shape. Changing your gait will not have an effect. If they don't hurt, leave it alone.