Yes, this quote ...
I think that she will say "I need you" after many other events where she can make sure that she can trust the main character. After one day of dating, it would be strange to hear something else.
And yet, the quote can be interpreted in the literal sense, and in the sense that a strong Minthara does not want to show her real feelings because love is pain.
I think she is strong both inside and outside, but every strong person has his weak points, which only a select few know about. In the first act, the main character is not the chosen one, but the candidate on the long way to this
No.. that hit me a lot deeper on a philosophical level. It's not a lack of commitment, she lets you go and helps you, risking wrath of the Absolute, also sets a condition that you belong to her now and she in turn belongs to you, that is serious. The fact that your minds connected, hell knows how much that means and how much you saw, and if that one night was more quality time than many months of dating, only problem here is that your characters personality could be quite different, but it could be a headcannon that makes sense.
The fact that she wants you but doesn't need you is good, it's a luxury of choice, of free will due to the nature of being a self-sufficient individual. She doesn't need anything from you, she just wants you. Unless you mean ''need'' in the sense that the relationship with you specifically is so good that you would rather die than continue living without said relationship, so the relationship is needed for you to continue living, aka Romeo&Juliet.