Right, the warning for the employee_firstname` VARCHAR(255) is correct as looking in the DB it is still (32) you can easy change that with phpmyadmin or with adminer. I have verified this with a clean install, so that warning is easy to solve. Same for product table change the 2 fields to 64, the last warning about location you can ignore as it is correctly done.
But it should not effect your combinations... really turn on your debug and dev and check error logs.