We exclusively use the KJV version, and will never use the side-by-side comparison features for projection also. It's a shame that this half-baked version of MS doesn't include an easy way to remove all these extra Bibles.
However, the Bibles are stored in a simple SQLite database, which can be edited. The database is here on windows C:\Users\Public\My Shout\MS7\Bibles\bibles.sqlite . If you have a techie friend that knows what they're doing, you can simply download a program to open that database then run some queries to remove the extra Bibles you don't need.
This takes some knowledge of databases, which I have, and I was able to successfully remove all the extra Bibles we didn't need. This seems like something MS7 should be able to do without having to mess around like this though.