1. Is there many other wireless network around? You have changed the operating channel and situation improved, which sounds like there is interference. 2. If the two CPEs are at a different height,...

Can you access to this unit when wired connecting to it? Beside, would you please provide the topology?

Actually CCQ doesn't indicate the quality of communication. And compared to CCQ, signal strength is more significant. -70dBm is a good value. If you don't meet problem like low speed or packets drop,...

Would you mind using English? Not clear of what you mean. With Google translation seems like you get problem logging in the device's web management page. Mind to send a screenshot?

You're right that in such a short distance you don't need a high value of transmit power. But it's hard to estimate accurate proper transmit power. A field test is needed. I think the possible value...

There is two different concept. The both above model support RADIUS while neither of them supports Dynamic VLAN.