I’d recommend taking it step by step – and there are an infinite number of steps you can take with this hobby (or obsession).
If it were me I’d do #1 (so you can take advantage of the higher quality audio chain), and get a NUC and get Roon off the Synology so you have a more optimal setup for Roon and can take advantage of Roon’s DSP tech to tackle room correction (which depending on the room can make a solid to sometimes amazing difference in sound quality). And of course you can also experiment with upscaling and other DSP capabilities.
For room correction, you can do this with Roon’s convolution filter capability by either creating a filter yourself using REW – here’s a tutorial on how to do it:
Or have a 3’rd party company (Home Audio Fidelity) create one for you – here’s a chain on this topic:
I’ve done the later and had fabulous results…
This approach would get you to an optimal setup to run Roon, get you a high quality signal chain, and fix room issues and that would allow you to properly evaluate your current equipment setup. You can then decide where to go next (or not).
Of course, this is only my opinion and YMMV… Good luck on your Roon adventure!