Not with an ATX mainboard. After the lowest screw on the left of the mainboard, there are still 2 free slots. After that comes the sheet metal. Which means that air cooling makes no sense from my point of view anyway.

It's about the glass pane on the side → with "light" the glass is very transparent, with "dark" it is a tinted glass...

In the meantime, I know more than you do: Two single drawers and two multi-drawers are included. Additional ones are NOT available directly from the manufacturer, but from e.g. Steg, Amazon etc. at To be honest, I find it a bit tiring that you have the case in your range, but no extensions.

(Copy & Paste) No, the power supply unit is not usually included with this type of enclosure.

Yes it is possible just check the thiknes of the rad. But mostly yes.

Not at all. There are (unfortunately) more and more cases that do without 5.25" slots for such things. What is standard for notebooks today (no DVD/BR drive) is also coming to the big ones. https://www.hardwareluxx.de/index.php/artikel/hardware/gehaeuse/54568-fractal-design-meshify-2-xl-besonders-gross-und-luftig.html An additional external housing for the drive (yes, I know :-/) or a different housing.