Re: your second question about tracking your LPs.
Generally MC wants to manage files, so you can create stump files that substitute for your LPs, and tag away. You could create a bunch of text files, named in a format such as <Artist> - <Album>, and import these. Then you can pull these fields from the filenames, and you'll have a catalog. It is easy enough to create these files via script which reads from a sequence of titles.
Alternatively, you could create an MPL file that contains these fields. The advantage of this is you have one file that can be imported, thus populating your entries (which will have no associated Filename). I recently wrote a script to transform one exported database format into an MC-consumable MPL file. It would be easy enough to convert, say a CSV speadsheet or other well-formatted text file into an MPL file (the format is trivial).