Yes you can. Unfortunately, visissitude geives you an attraction opinion bonus, not raw physical traits. There are other ways, though.
The quickest fix would be to adopt the "Siren" hunting method.

How does it give an attraction opinion bonus? I didn't see that option either?
(And yea.. super-sad you can give everyone else traits - though they hate you for doing it - but not yourself)

First point in the skill tree. +10 bonus. You got better at supernatural makeup.
I guess it is realistic that you cannot straighten your own spine to get rid of the hunchback trait. Still, massaging your own foot or fixing your own nose should be possible.

It is probably a balancing concern. Powergamers could create characters with hunchback, clubfoot, ugly, scaly, lisping, etc. traits, get a bunch of character build points, learn vicissitude and beautify themselves.

My solution would be the introduction of some Cthulhu-esk event for over-usage of vicissitude. In the lore the discipline is an intelligent disease.

Other people hate you more when you give them bad traits. They also rightly hate you for abducting them. Involuntary subjects fight back and hate you for beating them up.
If you give them good traits they hate you and love you at the same time. If you use dominate or blood bond etc. and avoid combat you also avoid a portion of the opinion penalty.

Yes, with Will Over Form, you will still need to study the traits(prisoners with the trait you want to study), its really op, cause you can give yourself all the best traits, meanwhile give horrible traits to your enemies over long distance.
edit. It costs piety, and if you have intelligent but want to get genius, you have to remove it first, then add genius and so on, and you have to study them one at the time.
You also have to be low generation, think its 5.

Oh yeah. They have changed it. In earlier versions you had to duel involuntary targets before you could mold them. Now it just costs piety. And now you can edit your own physical traits at will. That is OP AF, especially with self-made characters.