Because Telus only has one data port enabled on the ONT, I need to get a switch. However I would like to use a managed switch so I can control bandwidth to my Google Wifi and T3200M router. Any ideas?
What we really need to know first is HOW does the router get an IP address from the ONT and is public or private (LAN)?
Because if the ONT is actually a router (which I doubt), it really doesn't matter how you set it up. But as it only has one port its probably acting as just a bridge and only one device will be able to get an IP address from it, in which case your idea plain wont work as you need a router connected to it in order to perform NAT. Connecting Google WiFi directly to the ONT simply won't function as it has nowhere to get an IP address from and no network to bridge the traffic to.
More than likely, you need to connect the router to the ONT using CAT5e and connect the Google WiFi to that. There is no temporary fix for that.