pleb_maximus

I see the problem with Switches 2 and 5. Because they don’t help anything if Switch 3 or respectively 4 go down. They aren’t connected to the Routers on their own. So with the current setup you could get rid of the whole row of Switches and not lose any redundancy.
Also, you could think of aggregating your cross connections in Port Channels. Might as well use your ports if you are paying for them anyways.

Oh, and are the WiFi and LAN supposed to be the same net? Because if they are, you don’t need to go over the routers to connect between the two of them.

Not only Dutch signs. They are pretty much standardized across most of Europe and some other places, thanks to the Vienna Convention on Road Signs and Signals.