This is an interesting topic to me.
A few years ago I used to race with a lad who drove a lovely smmoth line for a whole race, but just didn't carry enough speed. The car could have easily gone faster and still run the same line. He has now got a lot faster as he has built the speed up.
If you watch the recently posted footage of the Japan Nats you will see that Masami et al drive a perfect line very lap, kissing every apex and maintaining maximum corner speed. This is not necessarily an aggressive driving style.
My guess is there is more speed to come from you mentally.
Instead of being relaxed and happily running a good line with smooth inputs, get your head "in the zone". Drive at 10/10ths. Up the adrenalin and you will see that your tempo increases too. Your line can still be good and your inputs smooth, but you will find that with more focus you will make those smooth movements more quickly. If you are working the throttle and steering at 10/10ths, rather than 8 or 9/10ths, the car will be faster all round the track.