Here's the second beta of 5.0.2. It's got a number of fixes in a lot of different areas. There are exporting fixes, Full Screen changes, .mac syncing fixes, crash fixes, and more. Download it here:
MacJournal 5.0.2b2.
Unfortunately, you won't see an in-app update this time. I'm still getting a handle on the new system (the third-party open source Sparkle system) so the first beta or any 5.0.1 release won't get notified automatically. This shouldn't be a problem in the future.
Please download it and let me know how it works for you. I'm still very behind on all the email that has come in since the release, so apologies in advance if I don't get back to you in a timely manner. But I have read your mail and hopefully this build helps.