I know freepbx but do not see any in my customers locations. I do see a number of Panasonic PBX systems so, why not be cirtified and compete against the other resellers. What are the steps to be a panasonic reseller/integrator? Can the password of a panasonic be hacked if the client has no contract with the original PBX reseller? IS that even ethical?

You should contact your Panasonic dealer and they will arrange courses for you

You don't hack the systems. If the customer wants you to maintain the system then they can ask the last person maintaining the system to change the password or as a certified Panasonic installer you can ask Panasonic with proof of the owner to reset the password.

Ethics is based on the way you do business. If the customer is unhappy or can't get the installer to maintain the system I would take them on as a customer.
I don't like someone going in bad mouthing the installer and under cutting the price to take the customer as no one wins in the end.