Do I need to install the renderer on all machines?

RR does not have any renderer included.

You need to install the application you want to use on all machines that should be able to render with this application. 

Information for all Users

You can set a short info for all users working with RR.

See here.

Installation on Clients

If your application supports a commandline install or if you just have to copy some plugin files, then you can write a batch script.

Test the batch script manually on one machine.

Then load it into the submitter.

Change the renderer to "Once Each Client".

Send Messages

You can send messages via rrControl to each client (richt-click, other, rrMessage).

And as you can sort the client list after the person logged in you don't need to know the machine name.

And if the client is not on, the message is cached at the rrServer.

And if nobody is logged in, then the message is cached at the client until someone logs in.