I need better Aspects.
I need to be more active in compelling Aspects, and explaining why.
I need to remind players about Aspects, and about compelling them, and about using their own Aspects to improve (or replace) rolls.
I need to fill out the NPCs I've got, and I need to either write more encounters, or get better at making things up on the spot.
We played through the opening scene(s) of the game on Tuesday night, and the rest of what I'd written so far tonight. I think it went pretty well, overall - everyone seemed to get into the swing of things by the end, although my poor explanation of some of the less-obvious mechanics (which, for a group mostly used to 4e, is all of them) led to the list of necessary improvements above.
Combat flowed okay, but the bad guys were almost universally too easy (both in physical and mental combat); the players were surprised at how easily they dispatched the first set of enemies - with the exception of their leader, whose escape was laughably easy. I should have explained the concept of Conceding a conflict, and the other enemies should have been capable of absorbing more shifts before dropping. An all-minion mob makes for some epic hits, but rather a low-peril encounter.
Tonight's scenes ended up being a lot more socially-focused than I'd envisaged; after taking out one bad guy, a player managed to talk the other two down - a scenario I hadn't adequately planned for. I should have had a better idea of what they know and would be willing to say.
I ended up having to change a bunch of details on the fly, even to the point of retconning conversations and inserting player knowledge they didn't actually get to have the rest of the evening to flow smoothly, but everybody was aware of the beta nature of this playtest so it worked out okay.
I have even more notes tonight than I did previously, and a whole bunch of things to improve (as well as a massive gap in the story that's yet to be filled in), but I was a lot more comfortable and confident running the game tonight than I had been at the start of the week.