Kopul HDA-525 Premium High-Speed HDMI Cable with Ethernet (25')

Yes, the Kopul HDA-525 Premium High-Speed HDMI Cable with Ethernet is fully compatible with your 1440P Monitor, so long as the model has HDMI inputs, and your PC has an HDMI output.

I'm a 65 year old and a retired chief engineer of a major Hollywood motion picture studio. Hopefully, I can help answer your question. When a cable manufacturer says that their HDMI cable is with Ethernet, they are saying that they their cable supports that particular function of the HDMI V1.4 standard. Being that it supports Ethernet communication over the cable. Often that V1.4 standard also supports digital audio passing over that cable in BOTH directions (in AND out from the TV). How that Ethernet communication over the HDMI cable is used is a different question. Basically, it provides for Ethernet communication between the TV and the device it is connected to using the HDMI cable. Often that Ethernet communication is simply the coordination of the 3D information provided by a 3D Blu-Ray player. It CAN be used for connection to an internet connection for access to streaming programs, but I haven't seen many examples of that use. There could be many other uses also. It all depends on how your TV might use that signal path. In a practical sense, an Ethernet connection over a HDMI cable DOES NOT preclude your TV using a WiFi connection to the internet for streaming services (Netflix for example). If WiFi is the most convenient method of getting the internet to your TV, then use WiFi. If WiFi isn't reliable enough, as it often isn't, use a discrete (standard CAT-5 network cable)

Yes it will.

I'm sorry but I do not have an answer on the 15' HDA-515 Premium High Speed Cable with Ethernet 4k at 60fps question.

I have no experience w/4K via HDMI. I use CAT 7 cable direct to router for 4K content ..