When set to auto, normally the router will select a better channel to use

You mean WiFi password? Just access the 901 web UI and find it, simply reset it then use the default password printed on the bottom. If you forgot the web UI login password, reset is the only way

how do you want to set up Open DNS? I saw some cases that they need to block the port 53 and limit some IP addresses, and that needs to be done on access control filtering. It's available on version...

what is the wan IP address?

I think the new released version solve the issue already

You may try different channels for the wifi and the largest channel width, regarding firmware update, you need to note that the hardware version cannot be changed, that is to say, you router is v2,...