If you look at the close-up picture of the interior, you can see the cooler covers the closest ram slot and it almost touches the closest ram stick. These are some fairly tall sticks, but no issues with clearance. If you wanted to use 4 DIMMs, you might have a little trouble on a mobo that has the ram slots so close to the socket. You'd have to lift the fan on the cooler or move it to the other side. This is a fairly small mobo width-wise, and I know most others are a little wider so your mileage may vary.
The glass is pretty dark and much darker than anything else I've seen. I have memory of the S340 Elite and the Phanteks P400S TG and both are very easy to see through and only lightly tinted. In comparison, this is much darker and it is hard to see anything without lights on it unless you look pretty closely (this is in my fairly dim room). However, I think a pair of led strips would certainly brighten it up enough for you to see everything much easier while keeping the nice aesthetic of the tint.