Why use ftfpd32 to update? Is it third-party firmware? Did you reset the router?

No access point or bridge on this router. Try set the Xbox as DMZ host, or open ports. It's quite common to have NAT issue on Xbox. Just go search you will garner tons of suggestions.

Seems router is bricked. Contact tplink support for solution

What's HW and FW version? Did you try on other computer?

What settings do you have from ISP? I guess you can refer to the installation guide to run quick setup. It will ask you to put in information from ISP.

C7 is just a wireless router while VR600 is a modem router. Be careful what you choose. If you are looking for something to replace the BT hub which I think is a modem if you have to plug phone line...