very complicated amahi+network setup

[nalleju]

Before you do anything make 100% shure tyhat the Cable modem do work.
They are not very reliable and most cable companies do a terrible job.

The setup I would use for this is wired all over. Security on WLAN is a joke, 10 sec to brace into a normal WLAN. The only ones trusted are the special security devices, only bad with them is the astronomical cost. Also the overhead on WLAN is as best high and with bad reception extreamly high.

But...

Connect Amahi to the Cisco. And use it as an modem.
If needed put a small switch (cost €10,-) and connect the AP, printer and PC used for banking to it.
Use the AP as an AP withouth any DHCP gaitwaing...
Some units requires you to connect the switch into its LAN ports and not its WAN port.