Seems reasonable, if you want to make it a non-advanced talent. The line there is pretty blurred, honestly. None of the normal rogue talents have prerequisites, so I think it'd be fine if someone wants to focus on initiative that much. I'd keep the cunning cost.
Nice to hear that. About normal rogue talent with prerequisite Major Magic has, as it is a obvious advancement from Minor Magic. I'll make Quick and Amazing Reactions this way. =]
Also, unchanged talents coming from ninja that have a saving thrown (like Choking Bomb), we should change the DC to use Int modifier instead of Cha modifier?
Yes, all talents DCs are based on Int, unless you're a Panache rogue, in which case they're Cha-based.
Grit (Ex): A rogue with this talent may choose one 1st level deed from the list of gunslinger deeds and one grit feat that he qualifies for. He may spend cunning to activate these abilities as though he were spending grit. A rogue must have Exotic Weapon Proficiency (firearms) to select this talent.
Is that intended or an oversight? Maybe it should be "or". One deed AND one grit feat is basically 2 feats.
Sort of. The normal rogue talent grants you the Amateur Gunslinger feat (which gets you 1 grit at the start of the day and lets you gain up to your Wisdom, using the normal gunslinger rules, and gives you access to one 1st level gunslinger deed). It also lets you select one grit feat.
There are two differences between the core rogue talent Grit and this one.
1. You can theoretically take the Amateur Gunslinger feat as well, giving you access to two 1st level deeds and one grit feat.
2. This talent doesn't give you a separate pool of grit, it just uses your cunning pool.
Really liking this idea and dotting to follow further...