How to Decode and Play DSD Music from Windows?

[pone44]

I noticed that there are websites like hdtrack.com that sell high-fidelity versions of commercial music. I am completely confused by what software and hardware I need to play their products. The answers they send me from their technical support pages are things like "we do not recommend hardware or software". That is a lousy way to educate people about what their product is and how to use it. Maybe someone here can do better.

I noticed that there are many small amps available today that take digital inputs and use a hardware DAC and built in power amplifier to then feed the signal to regular analog stereo speakers. Typical of those amps is this one on Amazon:
https://www.amazon.com/gp/product/B00MA6O1F2

The same vendor, however, makes a version of this amp that also decodes DSD files, apparently this assists in decoding compressed files more accurately? The DSD amp is here:
https://www.amazon.com/Pro-Ject-Amplifier-MaiA-DS-silver/dp/B01M01UK6E

So questions:

1) How would I feed the hdtracks.com files from a Windows computer to the amp that decodes DSD?

2) Does it make any sense to instead use a player on Windows that can do the decode of DSD itself, then feed an uncompressed audio signal in 24/96kHz or 24/192kHz directly to the amp that does not decode DSD? What are the best audio players available for Windows that support DSD decode and allow playback of high fidelity audio files? I would prefer a GUI based tool that is easy to setup, install, and use.

3) I noticed that most of these amps are taking the digital signal from a computer via a USB cable. Why are they using USB instead of a HDMI or displayPort cable?

4) It is also confusing to me how these DAC amps are claiming to support 24/96 and 24/192 over optical audio (TOSLink) connections. I thought that these optical audio cables were somewhat bandwidth limited, which is why many bluray disks require the higher resolution audio to travel over HDMI instead?

I keep waiting for all of this stuff to simplify, and it seems to me it never does. It's always a constant battle to figure out:

a) What format is the content recorded in?

b) What can I use to decode the content and how do I set up software/hardware/cables/switches to enable the correct path?

I just want to play back high-quality music. I don't want a new research project every time I play a song.

[Marsia Mariner]

2) Does it make any sense to instead use a player on Windows that can do the decode of DSD itself, then feed an uncompressed audio signal in 24/96kHz or 24/192kHz directly to the amp that does not decode DSD? What are the best audio players available for Windows that support DSD decode and allow playback of high fidelity audio files? I would prefer a GUI based tool that is easy to setup, install, and use.

foobar2000 + the following plugins: foo_input_sacd and foo_dsd_asio.

Many moons ago, I did give a try to the SACD plugin, and all I can say is, it worked as expected.