I'll take a stab at this
The first 6 episode function was to establish without a shadow of a doubt that Hiro and 02 are made for each other, they found their wings. However, they now have to fly - or remain in flight, it's the same -: the purpose of the doctor's statement is that this "initial commitment" is not enough, and that there must be some effort on Hiro's part to maintain their relationship, otherwise it will fall apart, i.e. not getting strung along by his semen demon, because that is not being equal partners.
Being interrupted while discussing the kissing seems like it's meant to make us realize that it is indeed something serious, even if 02 teased Hiro about it. They then used the interruptions to either drag it on, or simply telling us to remember it, as it will be a plot point.
I also see Ichigo's tentative "confession" as a way to salvage what's left of her once privileged relationship with Hiro, we shouldn't disregard her>Don't give all your attention to 02, look at me too
I know it might seem like it isn't consistent with her behaviour, but I do think this is what is going on.>If you are really going to dedicate yourself to 02, at least spare some time for me, ok?
Her>I wish to be with you forever
might just be an extension of this, a>It's fine if you choose 02, just don't leave me behind. Being behind you is good enough for me. Her reference to the kiss might be a last desperate appeal to not be completely cast out.