Can Flint 2 have more than 2 networks (SSIDs)? My goal is to have 2.4GHz and 5GHz with regular network and 5GHz with VPN running as an additional network, so I can quickly switch between countries.
In addition, can I have multiple VPN countries set up on the router?
Yes, by using luci.
No, sorry - not with GL firmware.
For having different networks over wifi you can follow this:
https://openwrt.org/docs/guide-user/network/wifi/routedap
But since that is using the CLI you may also want to watch soms videos by onemarcfifty to get familar with the ui.
though i want to advise to use the guest network interface vs creating a new interface because only lan and guest are covered by the scripts for vpn policies.
No this is not possible, the vpn software inside gl-inet does not support multiple vpn clients, the normal OpenWrt without gl-inet software does, you can do a 'split tunnel' and route different local ips to different vpn or wan.
But guest wifi with vpn policy work for this scenario.