If I use my keys on my ps3 will I still have my full number of keys on the handsome collection PS4 since they come from the same shift account?
i would have thought you would as its still 2 different saves. you still will have one profile save on ps3 an another on ps4. dont take my word for it but i cant see how spending one key on ps3 will effect your ps4 save. especially if you were to do it offline.
Keys from PS3 do not transfer. GBX have said this.
If you have some keys on PS3, spend them there and transfer the gear over to PS4 via a character transfer.