Dentists can change the shape of your teeth in many ways, including sharpening them. They can install a bridge over your existing teeth that is removable, or laminated, they can cap them and also file them.
Yes, a general dentist could sharpen your teeth to make it look like fangs. It would be best to let them do it than doing it yourself for not only do they have the right tools, they also know better.
Yes, a dentist can sharpen teeth with a file and usually only do in order to fit various prosthetic devices. Some people have had this done for cosmetic reasons to look like they have vampire teeth.
