You could implement user permissions, and have a different user account to start and access the Wowza services/installation directory. If this is not possible, then you could inquire with our Sales team on a USB-locked license, so that access to the license key file would be moot without the USB device to activate it.
The way the Wowza is implemented it is very simple for a technician which we have very little control to login and steal the license key. This has happen previously to us,some months ago we discovered a number of instances been used in eastern european servers.
I would like to suggest a number of ways that a system could be implemented that would provide more security, for example that every new instance or new server the IP of the server be entered by the customer on your company dashboard.
This already happens, most software with license key are based on a domain and on the IP, for example WHMCS. Another solution would be a key generator on your dashboard were the customer would enter the new IP and a key would be generated which would work only on that IP.
We appreciate your suggestions and I will submit your comments to our feature request backlog. Although I cannot guarantee if or when this feature would be added, all requests are considered by our Engineering Team.