Hi Guys-
Forgive me if I’ve missed the answer to this somewhere but:
If I write something in the beta, and then the beta gets updated, am I going to lose my progress? Are the updates to the beta just like regular updates in any other program, or am I going to have to import my work from a back up?
…I’m not sure if this question even makes sense outside of my head. 
Anyway, thanks in advance. 
What’s happened the past 3 times is that they’ve updated things (2 minor, where we just replaced the .exe file and 1 major–the most recent–where it was a complete reinstall of the project), we haven’t lost anything. Just to be safe, I wouldn’t save your project files in the scrivener directory, and always back up your work. (There’s a note about only backing up as a zip file, as well, in Lee’s most recent post.)
Yes, it should always work like most programs when updating. No user data is stored in the application folder, but rather in your account’s hidden appdata folder, and your projects should all be stored in your account somewhere—like a folder created in My Documents. Most of the updates thus far have just been .exe swaps, so not even the Scrivener application folder is changed, but like I say, there shouldn’t be anything user specific in there anyway.