Question about Ubiquiti UniFi WiFi 7 Pro-Max

Sorry, I understand that it's disappointing, but the Swisscom router is in use here ;-)

yes and no... the easiest way is with a Unifi gateway (the controller then runs on it), otherwise you can also run the controller (software) on a Linux VM. It doesn't have to run permanently, but you need one to configure it.

It depends a bit on what requirements you have on the ISP WAN side. However, I would not use an Ubiquiti router directly in the WAN. Their security reputation is too poor for that. The Ubiquiti cloudomania is also very annoying. I use the new Gateway Max here, but in the internal LAN as a WLAN router, with a separate WLAN network. Unfortunately, Ubiquiti has already had some security problems and their communication has been poor to completely miserable.
On the WAN side, other router and firewall equipment is in use. However, you still need a Ubiquiti controller. Either with the controller software (free of charge) on a Windows/Linux/MacOS system or as a separate Cloud Key Controller. There are also Cloud Gateway routers from Ubiquiti, which contain the CloudKey components. However, you should make sure that the routers can also cope with 2.5 Gbps. Whereby the gateway routers like MAX only manage 1.5 Gbps throughput on the firewall & NAT. The Gateway Light devices are very limited and not recommended. If necessary, use a third-party router with a 2.5 Gbps LAN port and CloudKey(+) in the LAN or a PC with controller software. It depends on what requirements you have and what WAN connection is available.

UCG-MAX