There’s a number of existing feature suggestions addressing the potpourri of topics in your post
You can already configure your library to prefer embedded metadata and files over online media sources. ⋮ > Manage Library > Edit... → Advanced > Prefer local metadata
I suggest you comment/vote in those instead of creating a duplicate suggestion which will result in votes being dispersed/distracted (also sticking with the guidelines for the feature suggestions forum).
Therefore closing this post.