What security risks would be caused by using a wireless router with no encryption for the wifi and by configuring it with:
vi /etc/config/wireless
option isolate 1
"HW" isolation. Running OpenWRT. In this way, the wireless clients would be separated and wouldn't be able to capture each others traffic. Or are there still security problems, because a wireless client would still be able to say: "I am 192.168.1.1, route the traffic through me" - even when using "option isolate 1"?
the wireless clients would be separated and wouldn't be able to capture each others traffic
That's not true. They will still be able to capture traffic all they want, but they will not be able to communicate with each other intentionally. – forest Jun 1 '18 at 0:48