We would advise reaching out to the manufacturer for clarification.

120mm fans x 2 for front panel (optional), effectively cool the HDD & graphics cards installation guide: https://www.bhphotovideo.com/lit_files/452875.pdf

I ordered this, but was sent an MX330-G, which has the tempered glass, as described in the specs. The case is the same otherwise, although the carton is a bit taller, to accommodate an additional foam pad at the top of the box. The MX330 has the acrylic side panel, which is fastened with thumb screws, just as is the tempered glass side panel on the MX330-G. However, the MX330-G has stand-offs at the side panel mounting positions, with rubber shock cushions on those stand-offs, to protect the glass panel. Both side panels have a sort of "smoked glass" appearance, so the look is nearly identical. There does not appear to be any other difference between the two models.

This is an empty computer case. The performance of the computer would depend on what parts you use.

The manufacturer has not specified the dimensions of the panel, however it can be ordered directly from Cougar as a replacement part.

3 pin and works great. I bought 4

The expansion slots on the COUGAR MX330 Mid-Tower Case BH #COMX330 are punchout and not reusable.

I'll attempt to explain. Firstly, it should say "supports 5 fans." They supply one of the fans at the rear. However, I do have six in (I inserted 5, plus the one they supplied) adding two at top, two fans at front inside, and then found a way to put one more at front by lifting the front lid off and putting it in-between. So that's 1 + 2 + 2 + 1. Consider that a hack job (the sixth fan kinda looks out of place), but it's ok.