I thin leaving it wide open so that anyone can execute a test in community version is not a good idea.

It would be good to introduce a Read Only user into the roles listing. This user has the ability to only view items in the database and cannot execute tests.

In doing this you eliminate the risk of someone executing a test using a test case on a project without you being aware.

We all know what users of systems are like when they start looking at them. if you say "Don't Push the big red button" the chances are they will just to see what it does