I think the answer depends on a) people opinions and personal preferences and b) what set up you have in terms of PC hardware and how you are outputting the music to your hi fi. Several folks will recommend that you minimise the load on the media pc that is responsible for the audio output by running roonserver only and then using a remote client.
In my setup, it just made sense to only install roonserver on my media pc under the TV and then control it via my macbook, android phone or ipad. The media pc outputs the audio to a Raspberry Pi over the network which has a HiFiBerry Digi+ add on card which in turn sends the digital signal to my Naim DAC.
I think you might need to think a little more about what the full package includes.
But the short answer is no. Unless it makes you feel better in some warm and fuzzy, new-age, shakuhachi-tinged way. In which case, turn off all your translation tools and stop using online dictionaries, which you really shouldn’t need anyway.
No, not at all. The only difference is that RoonServer does not have a GUI interface and has an option to launch at startup. So if you install RoonServer you need to have Roon installed somewhere else as a client to configure the server. You can indeed have RoonServer installed and install Roon on the same machine as a client for setup.