Should we periodically 'refresh' the mirrored copy of a SQL Server database?
I don't trust mirroring 100%, but I do trust it about 99%, same with everything else. It never hurts to periodically check your mirror database and DR scheme. We test our DR plan across the board several times a year, and it would not hurt your scenario to set aside a DR test time and simulate a failure of your primary database to fully test the mirror if you have concerns.