For the sake of DRAMA!, what we saw of Elliot's first time flying was a moment of coolness. Elliot's reveal was after having blocked a fireball, and floating defiantly between Justin and a fire-guy.
I don't think it will surprise anyone to learn, however, that the flying leading up to that reveal was awkward as all heck.
If Cheerleadra looks a bit different to modern Cheerleadra on this page, it's because Elliot didn't change their face at all the first couple times using it. It was only after this incident that Elliot modified their face and hair color slightly to differentiate from Ellen (mostly, Cheerleadra has a less rounded nose, thinner eyebrows, and lighter hair).
Names, Pronouns, and Politeness
It's worth noting that these are private thoughts that George is having in his mind-brain, and that he remains uncertain, within his understanding of the situation, whether Ellen thinks of "Ellen" as the only name she wants to be called.
This is further complicated by (minor spoiler) George being fully aware that Elliot still sometimes goes by Elliot.
I say this is only a minor spoiler because Elliot does a review show with Susan that George is likely aware of given who he frequently spends time with, and it's entirely reasonable that George could have seen Elliot at various other points in time.
All that said, calling anyone by their dead name is very likely to bother them (to put it mildly), and adjectives such as "formerly" don't make it better. It is highly recommended that one does not do that.
It's also advisable to correct one's self even when thinking, because the filter between mind and mouth is sometimes asleep at the wheel. Not getting into the habit of using the right name can result in unintentionally saying something hurtful.