One of the things I got confused about is the physical backup location. If you reconfigure the SQL Server to store new backups at a different path they don’t automatically start saving there.
You need to delete the Backup Devices in Server Objects too, otherwise it will still try to store them at the old location.
To use transactions within SSIS the MSDTC service is required. My company changed our AD structure and no one noticed no ports were forwarded for MSDTC. Since all SSIS Packages would run into errors I used DTCPing and DTCTest to check for a connection. After forwarding the required ports (TCP 1024-65535) it finally worked.
To migrate a Report Server we would backup ReportServer and ReportServerTempDB, drop the new default databases and restore the old databases on the new server . . .
The first more or less large migration of databases happened in November. I was still inexperienced so of course lots of mistakes happened but besides . . .