According to the readme for the agent 4.0:
Installing without requiring specific user privileges
Use this command to allow all users access to agent files and registry, regardless of their user privileges.
framepkg.exe /install=agent /defaultpermissions
I read this as allowing the install to continue even if the logged in user only has user or power user rights in Windows.
I tried running it locally on a PC but still get the error that admin privileges are required.
Also is Agent 4.0 compatible with EPO 4.5? I could not find a confirmation either way.
That is incorrect. By default, when the agent installs, it assigns specific rights to the files and directories it installed, this switch will effective give everyone full control to its installed directories.
You still need admin rights to install the agent.