This is my suggestion for easier relocation of missing files:
1. When trying to play a missing file, a pop up appears that lets you paste the new file location (e.g D:\Music\new location).
2. When a file is relocated, other missing files from the same album are automatically relocated (maybe a prompt would pop up saying "Relocate other files from the same album?")
3. When you right click a group of selected missing files there is an option to scan a specific folder or group of folders to find the missing files.
4. When files are relocated, data stored in the MB library (play count, date added, etc) is preserved. Currently, MB does not keep the play count and date added of a file when it's relocated.