No it can only work in 5GHz channels. And different regions have different available channels, you can check in wireless --> channel list

I think the CPE210 is planned to compete with UBNT Loco M2, as a 2.4GHz AP with 9dbi MIMO antenna, it should be able to work well for 3Km in a point to point link. CPE210 probably works for 5km, but...

Obstacles in the way and metal structures around the device will cause packet loss. Ensure the two 7510N maintain good line of sight and there is no obstacles between them. 1) Configure them as AP +...

I get confused about your topology. Here I use "-----" for wire connection, use "))((" for wireless connection. I know how you connect your modem and router: Netcomm 3G27WV-R 3G modem ------- Linksys...

For now only CPE510/CPE210 is 24V passive PoE input, they belongs to the same series named TP-LINK Pharos. I think there will be other Pharos products come out later. But don't try to use passive PoE...

CPE510 in AP mode, WA7510n in Client Mode. Disable MAXtream on the CPE510. That's all.