Dark Qiviut

As previously said, romantic interest can begin anywhere. You don't always start with a detailed analysis. And it's actually pretty common to be flustered around a crush. By the way, she was flustered long before Flash (being thrown into an alternate universe can do that to ya). Twilight centered herself towards the end, just as Flash became flustered when asking her to the dance. Pretty straightforward stuff.

That's the point. Flash Sentry attitude towards her is no different how could act anyone else. For this the romance between those two has nothing interesting. Pair Twilight with anyone else on ponyville and, name aside, there will be no differences.

Love can begin anywhere just like it can end quickly.

I really do understand where you're coming from. And I agree that there isn't enough to solidify that relationship yet. That's why it'd only be a start. If they built on it, then it could feel real (just as they could with anyone else). Flash and Twilight were never actually a couple. It was just a little crush.