A lower dose would probably result in slower changes. I've heard of singers using a smaller dose to try to make the transition easier on their vocal chords, but I don't know how effective that is.
I think T's effects will be based on your father's side of the family, if not your father himself. That's actually already true for me, I look a bit like my dad, a lot like one of my male cousins on his side, and nothing like my mom. Maybe I have her mouth, a bit, but that's it. As T's been changing me... I don't look like any relative I know of.