Neither issue is really a problem with Openmediaplayer.
the recommendation I had seen was to use "touch filename.extension" to change modification time, causing tracker to reindex the file.
tracker-process -r should work.
only other recommendation i have seen is to remove the tracker folder as a kind of last resort.
Mussorgsky is seperate issue. Removing databases causes album art assigned by it to be lost and need reassigning. As mussorksky isn't working (updated bing api broke functionality) you can't reassign them.