Codecs must be installed automatically during the software installation. Make sure that you have the latest version of the Viewer and the Host (Server) installed on the local and remote PCs respectively.
If you still get the error, please report here and we'll see further what the problem can be.
The Customer is free indeed to use the existing features of our software as they want. But again - Remote Utilities is a remote administration tool, not surveillance software. Our position regarding the warning banner in the remote camera mode is firm and won't change. Sorry.
If you mean version 5.1 it's been available since the 12th of December :) To be exact, the most recent version right now is the version 5.1.1. It's downloadable here. Also, refer to this news for more information.
Regarding the tunnels etc. RUT does not create a VPN tunnel. However, if the network environment on either side (remote or local) is restrictive and only allows port 443, the program automatically uses port 443 provided that you connect using the Internet IDconnection.
Also, in the version 5.1. proxy settings are available for both Server and Viewer.