Photo and File paths in AppSheet are relative to where the Google Sheet is stored. If the images are not stored in that same folder structure it will not be able to find the images.appsheet> data > App Acontains Photos and Sheet Aappsheet > data > Ap...

If you need sequential numbering, I would suggest leaving the ID as UNIQUEID() to guarantee a unique ID for each row, then add a created column as a date time and a record_number column. The record_number column would then use a spreadsheet formula R...

I've never deleted an app I needed recovered, but a client of mine had done so. He contacted support and had it resolved in minutes. I imagine if you talk to someone directly it goes a lot faster than if you send them an email.