Why do I need a switch?

I don't think you are going to get better sound, but anything with copper that goes through the outside wall of your house can be a surge path.

I use an outside gas discharge based surge protector on the coax and air gap via Ethernet to fiber converters. 

You will get better sound. Get a decent switch like an English Electric 8 switch. Run your cat6 into it. Place the switch near your rig so you can use a nice Network Acoustics ENO ethernet cable into an ENO passive filter up into your server. Your system will sound much, much better without a doubt. You can try these pieces with a 30 day trial and hear for yourself what you are missing.

You have not heard what your digital streaming front end is capable of yet. One caveat. Your streamer/server needs to be good to realize the improvement. Not sure if the Node is one or not. I have not heard it.

The Network Acoustic products are the real deal and easy to use.  A $40 switch will not improve your sound on its own.  In fact, it may well add more noise and sound worse.  

@grannyring can you give a rough indication of how much investment is needed to follow your experiment? Thanks!

@grannyring ,

But won’t my signal only be as good as what comes out of my router?

@erik_squires 

Are you talking about those things that are @$67 for the pair on Amaz—? Or some other brand? 
 I have never heard of gas discharge surge protection.  What air gap/gas line products do you use?

Thanks