It is a good idea, even if the fact to be able to play arcane archer regardless of the class is already very good and unique, the cost in AP make it really restrictive and ultra focused. As core enhancements have levels requierements, I think it could work like this:
Racial Arcane Archer ( all core cost increased to 2 AP)
-Core 1: cost 2 AP ---> Same as ranger AA AND you also gain the feat "Bow Strength" ---> Avaible at Character lvl 1 (ranger got this feat lvl 1)
-Core 2: cost 2 AP ---> Same as ranger AA AND you also gain the feat "Rapid Shot" ---> Avaible at Character lvl 4 (ranger got this feat lvl 2)
-Core 3: cost 2 AP ---> Same as ranger AA AND you also gain the feat "Precise Shot" ---> Avaible at Character lvl 8 (ranger got this feat lvl 4)
-Core 4: cost 2 AP ---> Same as ranger AA AND you also gain the feat "Manyshot" ---> Avaible at Character lvl 15 (ranger got this feat lvl 6)
-Core 5: cost 2 AP ---> Same as ranger AA AND you also gain the feat "Improved Precise Shot" ---> Avaible at Character lvl 22 (ranger got this feat lvl 11)
Like this, you can have an avaible AA racial tree, opening lot of interesting builds possibilities. The fact to get similar feats at higher levels make it in my opinion balanced for a cost of 24 AP minimum.
Even if I really like this idea and think it s a good thing to have AA as a racial enhancement if you want, it s still an opened door for all other race to get a class enhancement tree as racial. (Half orc --> Frenzied Berserker, Dwarf --> Stalwart Defender, ect....)
Yes, I must agree with this but not 100%. Ranger AA DC based on Wisdom only is logical but for the Racial AA, it should be Wisdom or Intelligence only. No reason to be able to get charisma as DC for an AA.