1. Yes it's a standard printer cord. Make sure the cable is rated for USB 2.0 speed to support playback of sampling rates higher than 96 kHz.
2. I would go for a longer USB cable and shorter RCA. USB 2.0 is limited to 5 m or ~16 feet. I think the Amazon Basics cable comes in a max length of 10 ft. which would probably work well in your setup.
3. Windows 10 is fine.
4. Thesycon is the driver for the USB interface on the DAC. It's normally unnecessary to install a driver if you're using Windows 10 / 11, but if you're having trouble getting the DAC to work, then installing the driver would be a possible solution.
If you're only listening to downloads that come with an LP purchase, Windows Media Player should be fine. If you ever want to listen to hi-res downloads (e.g. from HDtracks), then I highly recommend using foobar2000 with the WASAPI component added. It's free and works well.