Cats will piss in your sump or tank if they get a chance. I don't know why. But I almost lost a tank full of Africans that way.
Good job on the build. The tank looks awesome. I thought I was gutsy taking apart a 190g and putting it back together. 12mm thick glass equals roughly .47". I've always heard you should use at least 1/2" thick glass for any tank 30" and taller. But, since it was successfully set up for 5 years previously, I guess you should be ok.
I respect your tackling a job that big. And good job doing it. This kind of thing is what makes MFK so great. Good on you. Bubblegum and Northern Lights for everyone. Must be nice to be in Holland too.

Seriously, good job and thanks for all the pics.