System- so many questions

I’m just trying to figure this streaming stuff figured out! I’ve searched these forums and they tend to just confuse me more it seems. 
I’m looking for a “blueprint” for priority for improved streaming SQ to be upgraded over time.
 At present I’m Only streaming directly from the services and NOT using any stored music on a hard drive etc. but I’m not adverse to that especially if it would benefit SQ. 
My system- 
Odyssey Audio Kismet amp
Supratek Chardonnay preamp 
Bluesound Node 2i streamer/DAC 
Ascend Sierra 2EX stand mount speakers (pair)
Audioquest Niagara 1200 conditioner / protector W/ Audioquest Monsoon power cable
Audioquest Edison 15 amp outlet (not yet installed)
Rel 5/SHO sub
mix of Cullen and Groneburg cablesArris Surfboard SB6183 modem 
Netgear Nighthawk router ( not sure of the model but it was pretty decent about five years ago)
CAT 5e cable from router To Node
Cat 6 (I believe) from modem to router

I’m using Qobuz, Deezer hi-res and Radio Paradise streaming from within the Bluesound OS controlled by IPhone 11. I’m also quite intrigued by Roon and am thinking about getting into that as well. 
I’m only concerned about 2.1 channel and i’m also not wanting to stream to other rooms etc.
I really do think that I have a pretty darn good setup especially for the money but I would like to wring all the SQ possible out of it. 
Regarding money, please know that it has taken me quite a long while to get this system together and much of has been/ still is being financed. In other words, my funds are very limited and especially in these chaotic times. 
Ok now down to brass tacks: 
No strict budget because I’m looking to add things in the order of (hopefully) maybe a few hundred dollars at a time. 

 I would say that The Node 2i is the relatively weak link for me equipment wise and I am looking for suggestions as to a better DAC and/or streamer. 

Some things are pretty obvious even to me such as upgrading my modem , router and Ethernet wires especially since they need to be upgraded anyway for gaming etc.

Qobuz is recommending UBiquiti products and they look pretty good and fairly reasonable to me. 
The question from me though is exactly what to purchase and how to set it up? Would the addition of a laptop etc. be beneficial in terms of SQ and ease of use? I have two now but both are about 8 years old and were pretty low end even then. One has an older Windows OS on it ( which I hate) and the other has an older Linux Distro. I’m not very computer savvy and I suppose that all things being equal I would probably prefer something as simple as possible and not have to keep a laptop running constantly. Would a switch(?) such as Uptone EtherRegen be helpful and if so where would it go? Would an Ethernet cable(s) with built in filter be helpful? 
Sorry for the novel here but the only way That I feel that I could ever understand the best approach is to just lay it all out and go from there. 
Thanks!