The biggest concern I have is the loading times that I've seen on the Alpha videos that have been posted.
If it's taking seconds to load assets for a scenario start/restart, and all of the scenarios are based in the same star system (I haven't seen any others), then what kind of loading times are there going to be for travelling between planets, stars etc? And what kind of loading times can we expect for different types of vessel we'll encounter?
That is, unless the Alpha currently just flushes all assets regardless of their need and memory space usage vs capacity, and just reloads every time for ease of implementation (solely for the Alpha)...
I am very sure that everything is reloaded from scratch in the alpha, all games with fixed levels/scenarios usually do that. For the persistent universe, I expect significant amounts of caching, and some stuff, like all ship models, would only have to be loaded on startup and never unloaded again anyway.