I'm sorry for what you're going trough. Wish I could help because I never faced any issues.
1. That sounds a lot like an antivirus issue. It's possible your antivirus is giving a false positive and deleting the app. If you use multiple antiviruses try adding VeadoTube to the exceptions on all of them.
2. I never used the old version but it is possible that it doesn't work well with your microphone drivers. I suggest you stick to the newest version and investigate the "self" deleting issue which is very likely a false positive automatic delete from your antivirus part.
3. Probably a bug caused by this older version. Or because of the images you're using are too heavy for the app to handle.
Read the full documentation below, you'll see many tips regarding the issues you're facing there: