If you contact me here with what information you think you used to purchase, I can help track it down.
I'm really quite flat out with IPB 4.5 updates so although I'm open to the idea, I probably couldn't look into it for a while.
That's an IPS error, you'll need to contact them why your getting it. I don't have any control over that. Did you make a backup of your site before upgrading? If so, I can help restore the videos that way.
No not supported.
Permissions for each category if that's what you mean?
No compression, just raw video uploads.
File storage settings supported, so you can set the storage path like any other app.
HTML5 player.
I can setup a demo if you would like to check it out but the Videos app is really much focused on video sites like YouTube and only offers basic video upload support.