So I was interested in going into the arcane trickster class given the new options in the dirty tactics toolbox and was hoping to use it with the psychic. It seems like the perfect fit really given the int casting as well as the ability to wear armor without penalties. It still fits all the requirements as well except for the second level arcane spell. The GM gave me the green light to convert it.
So the only change that really needs to be made for the arcane trickster besides a ctrl-f and replace is the fifth level ability Tricky Spells
Tricky Spells (Su)
Starting at 5th level, an arcane trickster can cast her spells without their somatic or verbal components, as if using the Still Spell and Silent Spell feats. Spells cast using this ability do not increase in spell level or casting time. She can use this ability 3 times per day at 5th level and one additional time per every two levels thereafter, to a maximum of 5 times per day at 9th level. The arcane trickster decides to use this ability at the time of casting.
Should I just change this to cast spells without thought and emotion and call it a day? Or even forget about it really?
The metamagic feats to accomplish casting without emotion and thought (namely Logical Spell and Intuitive Spell) both add +1 to the effective spell level, which are the same increases as Silent Spell and Still Spell. That seems like a reasonable change as far as power level, if not entirely accomplishing the same thematic bonus as Tricky Spells.
Tricky Spells implicitly assumes that spells without verbal/somatic components can't be identified (thus the trick, they can't see you cast), but that's not true as of a FAQ a couple of weeks ago, so it doesn't really matter as much. Get Cunning Casting.
Have it grant Cunning Casting, with X number of auto-successes (before rolling) per day, where X is the number of times you could use Trick Casting.
I believe this is what they are recommending. Gaining Cunning Caster as a bonus feat at 5th level (or with other stipulations as suggested) might be more appropriate in keeping with the spirit of the Arcane Trickster.
That might even be a good thing to swap in for the actual arcane trickster...