If one of your public IP address will be used for only one device in the LAN, and another public IP adderss will be used for all devices in the LAN, then you can choose the router that support...

The backup link means that it will be only used when primary link down. So if you want to access the server through the backup link as well, then you can disable link backup and use policy routing....

If you have two WAN ports, you can set up virtual server for both WAN. It means that you can access the internal server thorugh both WAN ports. If you also set up link backup, then please note that...

If you mean that a part of your computers need to use two ISP links and other computers can only use one ISP link, you can set up policy routing to make the certain computers use the specified WAN...

Maybe you still need to go to Advance-> Traffic Control-> Bandwidth Control to make the function take effect.

Suggest to clear the DNS cache for your browser and PC. Because the router will block the packets based on DNS request. If you PC has the DNS cache, it will not send DNS request then maybe the router...