Though you can feel free to take the stance you are in, I will tell you that I feel it is a very poor idea and wouldn't get involved in a woman who felt this way without any willingness to debate the merit of it. The fact of the matter is that, in a fully developed relationship, sex is a big component. Not 50+%, not even the biggest component. But when something makes up a significant portion of the entire purpose of your relationship (along with friendship, companionship, someone to trust, social merits, someone to help you make sure you match, etc), and sex is a very important component of a full relationship, you want to make sure it is compatible.
Think of it this way. You can truly feel in love with someone who you cannot quite trust with your deep inner thoughts. You can have the most amazing life together ever, but you just don't feel comfortable telling them what going on deep inside your head and never do. (or vice versa and they don't tell you that stuff). Everything else is wonderful, but you just never connect on that deep level. The chemistry is fine, you adore each other, but you never understand each other on more than a superficial level. In time what you think is a minor flaw turns out to be something that drive you crazy about them and breaks the relationship. Its the same thing. Sex is a component of passion, you cna have plenty of passion without it, but if the sex itself doesn't mesh well between you two, you'll be married once you find this out. And it will drive you insane because it will be a very large gap in a very central part of your relationship and you won't be able to move beyond that mismatch. Likely it will lead to divorce or constantly wondering how much better everyone else could be.
Even if you were a fantastic sexual match, you may end up always wondering if it could be better because you haven't ever experienced anything else. Trust me when I say, it never happens the other way (where you have subpar and assume that is the best it gets) while doubting the supremacy of something great happens way too frequently for my liking and leads to too much resentment and cheating.
Now I've been with ladies whom I haven't slept with for well over a year of dating (and a few who I got into bed with comparatively quickly). Its all about making sure when you do have sex, you've thought about it and decided its correct. But I truly believe that for a relationship to be fully developed sex must eventually be explored together. Take your time and find when you feel right crossing that road, but avoiding it til marraige seems very foolhardy. It is a vital part of your relationship and, from experience, CANNOT be intuited from other things. Your sexual chemistry is wholly independent of how he kisses and dances. My opinion: If you respect marriage, you will not gamble with a future marriage by going in with a gigantic question mark hanging over its viability due to unknown sexual compatability. Its not something easily worked past