I would lead out again to gain some more information, because he smoothly calls you i dont put him on 10 10 - AA but maybe i am wrong. If he raises you i would fold because probably he is on the premium hands.. But i would definately lead out again for information

1) i would have limped in with 99 because this is a vulnerable hand
2) your flop bet was decent, maybe a bit too agressive i wouldve made that 3/4 pot i think