It's always good to keep it polite and remain civil Eric. Particularly if there is simply a terminology or communication difficulty, which I suspect that there is in this case.
Nothing you just described requires the JRiver Media Server to be running on your Client PCs.The only reason to run the JRiver Media Server on a PC is if you wish to share the contents of that PC with other PCs or devices.
In your case, I assume that you share the contents of the HTPC with the Living Room and Kitchen PCs, so it needs the JRiver Media Server to be running. If you also share the contents of the Living Room PC with the HTPC and Kitchen PCs, then it will need to run the JRiver Media Server. Do you share the contents of the Kitchen PC with the HTPC and Living Room PCs? If so, then yes, you would need the JRiver Media Server running on the Kitchen PC.
Also, in each case, if you had music on a PC and wanted to be able to play that music on phones, tablets, and other devices, then yes, they would need the JRiver Media Server running.
You will notice that I am specifically saying "JRiver Media Server". So, terminology
JRiver Media Center GUI:
The main program, which when running can do the tasks of the JRiver Media Server as well as provide the user with a GUI. Can be started at Windows Startup or directly later from a Windows shortcut etc.
JRiver Media Server:
The component of MC that can be run independently of the JRiver Media Center GUI, and will allow MC Client and DLNA connections to the content in the Library loaded on the PC it is running. Can be started at Windows Startup or later via the "Tools > Advanced Tools > Media Server" option in the top menu of JRiver Media Center GUI Standard View. Sometimes called the Library Server, but that is a superseded term I think.
JRiver Media Network:
A feature of MC that provides the setup and communication functionality to support MC Clients and optionally DLNA Clients. The feature needs to be turned on in MC under "Options > General > Features" to allow access to the MC Client configuration, however, the settings at "Options > Media Network > Use Media Network to share this library and enable DLNA" does not need to be turned on for MC Clients to connect to a JRiver Media Server or JRiver Media Center GUI acting as a Media Server.
JRiver Media Center 2x Service:
A component of MC visible in the Windows Task Manager, which isn't the JRiver Media Server, runs whether the JRiver Media Server is running or not, and can keep running for a while even if the JRiver Media Server and GUI have been shut down. Prevents MC from being started again until it closes when it is finished whatever it is doing, or is closed manually. If JRiver Media Server and GUI were doing nothing when they were closed, the JRiver Media Center 2x Service closes immediately. If Service was doing something when the JRiver Media Server and GUI were closed, it can take a few minutes for the JRiver Media Center 2x Service to close. (Description included for clarity, given that this Service has been mistaken for the JRiver Media Server previously.)
I think Eric and you are talking about two different concepts regarding "Server and client content". Eric wants the client computer to have its own library, in addition to the server library so he could have the client record TV shows independent of the server. That is not possible.
Yes, I understood that is how he is using it now, but this new functionality replaces that need. Eric will need to move any content on the Kitchen PC to a location on that PC that is visible to the Server, and he will need to import that content into the Server Library, as part of the transition to using this new functionality. But a local Library on the Kitchen PC would not be required anymore.
The new feature of allowing clients to record should meet his need after he figures out how to control who can see what content.
I agree.
Eric has been running the Kitchen computer as an independent computer except when he needed to access the contents of another computer. I think that is why he was running Media Server.
As above, Media Server doesn't need to be running on the Kitchen PC for it to access content on another computer. Media Server needs to be running on that other PC.
This reminds me that with the new feature allowing client to record, we will have to put the client in Media Server mode too because we will need the computer running if we want it to record TV show.
I don't understand this statement. The Client needs to be running as a Client of a MC Server, so that it can have a copy of the Server Library with the Recording Rules available. It will need to be able to wake the Client PC at the correct time. It will also need to send WOL commands to the MC Server so that it can update the MC Server Library via synchronisation. While that wake process may take a little while, it does seem to be working pretty well now since Bob made some changes. Of course, I don't know if a MC Client woken to record a program will automatically send WOL commands, but currently any activity on the Client that requires writting to the Library does seem to do that, with some delay.
Maybe "putting a Client in Media Server mode" means something different to running JRiver Media Server on the Client?
But all the above is basic to the idea of having Clients being able to record TV while connected to a MC Server.
BTW Eric, if a MC Client is connected to a MC Server, it is dependent on that Server. There is no getting around that. Although theoretically, with recent changes, if a MC Client can't access the Server it is "connected" to, it will ask if it wants you to fall back to the local Library, and I think after a while it does that automatically. So if a recording rule in the Client copy of the Server Library woke the Client, the Client couldn't wake the Server and fell back to the local Library, and if the rule was also in the local Client Library, at that time MC should start the recording locally. But that would mean managing rules in two Libraries, much like now, and would probably be horrendously unreliable, as dropping such connections can cause issues, because they rely on DLNA protocols.
Did I miss anything?
EDIT:
The Shares and Drive Mappings required need to be done in Windows.