Old flames die hard

I've known this girl since I was 16 (I'm 28 now) and we've "dated" sporadically and rather non-seriously many times over the years. Needless to say, we've established a very comfortably sexual connection that never really went beyond physical gratification.

Well, recently, after a long hiatus, we've had the chance to get "reacquainted" and I noticed a deeper connection, an emotional one, that was never previously at the forefront of our interaction with one another.
I can say with certainty that it was a mutual acknowledgment, and she's hinted at wanting to commit to it.

Problem is, she lives about an hour away and also I'm somewhat suspect of her ability to maintain a meaningful relationship, as she has been known for some particular antics in the past, most of which she told me of herself.

I don't want to just break it off, because we have a lot of past together and I do care for her, but I'm stuck between growing feelings for her, and an uncertainty that I may be wasting my time if I pursue a deeper relationship with her. I want to believe that she's matured enough to make my efforts worth it, but I'm at a point in my life where I need certainties and must focus on my future. But I get the feeling that if I exclude her from it, I will have cemented a no-go for any future possibilities. (Not talking about the sex, although it's a nice bonus)

I can't presume to maintain a purely sexual relationship when feelings are now involved, but I can't seem to entertain the thought of severing contact with her either.

It's sort of an ultimatum that I'm not sure how to go about analyzing.
Any insight?

In some ways you say it yourself. It is either all or nothing.

When we start relationships with another person, risks are involved. It seems you are finding this potential relationship a bit too risky and you are worried you will get hurt.

The truth is - we cannot protect ourselves. You could meet the most loyal and stable person and still end up getting hurt. You can also date this girl, and end up having a wonderful relationship. There is no way of knowing. But only one way to find out :)

If I were you, I would say - go for it. Push doubts aside and give it your all. Just don't do it, if you feel you can only do it half-heartedly.

:)

Give it your all. I say go full throttle and what happens happens.