The only problem with self-hosting is that big coorps like google or microsoft will put you on their spam list, so your e-mails will land in the spam folder when you send emails to gmail or outlook addresses. Other than that it's not a huge hassle as stuff like https://mailcow.email/ or mailu or mail-in-a-box exist.
I just pay the qobuz subscription and use this inofficial script which can download the high res flac files from qobuz. (You can also buy music on qobuz and you get the flac file without drm or so as a download, compared to other services which don't give you the file itself)
And then I use jellyfin to host my music library.
Jellyfin has many music player apps which you can use.
Laptops don't have the same amount of cooling as desktop computers, so the same CPU in a laptop won't give you the same performance as in a desktop computer because of thermal throttling.
Lmao