Hmm. Okay so Music should be fairly manageble. Just have a local folder with your music in it and then sync it to your phone using Syncthing. Then you need to find a music player that you like and has the features that you want.
For Office Suite have a look at OnlyOffice. It’s pretty darn Microsoft Office compatible.
For 4. look at photoprism (https://www.photoprism.app/) it’s a self hosted photo management platform.
I don’t know about 5 though. It looks like the scansnap scanners are supported in Linux but I don’t know about batch scanning or evernote. This you will have to figure out yourself
For outlook replacement I suggest Thunderbird. I can’t help you find a music player. I know that ones with your requested feature set likely exist but the googling you will have to you yourself