I'd like to keep specialist talents as they are, they are special for a reason.
But I'll propose on the aptitudes issue by saying if you get the willpower aptitude twice in character creation this will substitue for the psyker aptitude for willpower advancement.
The pay off of course being that you lose out on another caracteristic app for cheaper Will since it wont be substituted.
Sound agreeable?
That sounds good to me.
Also, Witch Hunter Balthazar Thorne stands ready to serve the Emperor!
https://docs.google.com/spreadsheets/d/1HsPKw_D8WBYVexPe4yUn1mzHmlBZY5p31ftJ-abEx6Y/edit?usp=sharing
I went with a Shrine World Ministorum Crusader. I'll primarily be a social character, but I will also have some knowledge skills and melee combat ability. Crusaders get a really strange combination of Aptitudes (Knowledge, Offence, Strength, Toughness and Willpower), and while I risk spreading my experience too thinly across multiple specializations the class looks like a lot of fun to play. I'll work on a more detailed backstory for the character in the days to come.