192.168.50.1 and 192.168.50.4 show download and upload traffic. So you have internet access now?

Do not set WAN1 and WAN2 in the same subnet. Try to give it an IP like 192.168.2.1?

No. It's just an easy smart switch. Here is the compatibility list: https://www.tp-link.com/en/omada-sdn/product-list/

OC200 and EAP don't have WAN interface or DHCP Server. Both of them should get IP addresses from your firewall. You can check on Devices page if they obtain the correct IP addresses from your...

There is a TP-Link official guide for both standalone mode and controller mode: https://www.tp-link.com/en/support/faq/2814/

@Zeron Don't need different sites. You can select the SSID you want to apply to. But you have to buy an OC200. Hotspot portal has to keep controller running.