My Rating Ceiling

As I've started to take chess a lot more seriously over the last 18 months, I'm curious what my likely rating celing is given my natural intelligence, current age, and time to devote to the game.

I played chess very casually from about 15 to 33 (goofed around mostly on blitz and never read a chess book) and generally had about a 1400 rating. Over the last 18 months I've probably averaged 2-3 hours a week of studying and 5 hours a week of playing and now my longer time control rating is mid 1600s online.  Not sure how important intelligence is, but I think I'm on the brighter side (hold ivy league graduate degree in quant field). I think now I can devote a little more time to the game, so maybe 15 - 20 hours a week. I'm 35 years old.

It seems that those of us who start late are at a big disadvatage. Is it crazy to dream of being a national master or at least break the 2000 marker? What kind of rating increase would be reasonable to set on a yearly basis ?

Out of people who soar up very quickly are vast majority younger (like < 30)?

im not that high in rapid, but tactics and openings are important