Can You Use a Router for a WiFi Extender?

Yes, if the second router supports access point, bridge or repeater operation appropriate to your connection. Follow its manual and avoid having both devices run conflicting router services.

No. Access point mode generally uses a wired network connection to provide WiFi, while repeater mode relays a wireless connection. Check the router's documentation for the mode it supports.

An access point normally needs a network uplink, commonly Ethernet, though a model may document other arrangements. Use the connection method specified for its access point mode.

Possibly, but wireless repeating support and interoperability vary. Verify the specific models and supported standards rather than assuming cross-brand repeater operation.