Dual GPU or Wireless chip?

So during my build I was very naïve, everything I saw that cost a lot of money I just threw in the computer when building my alienware r4 alx. Now 2 years later I want to upgrade GPUs but I cant because the GPU slot is taken up by the wireless adaptor 802.11. I was wondering what exactly does that adaptor do? I feel like its unnecessary because my computer is 100% of the time wired directly to the router. So when building my aurora the options were no wireless adaptor and 2 single GPUs, or 1 Dual GPU configured single graphic card and wireless adapter. So I went with the radeon HD 8990 as it has 2 GPU I figured the work load would be distributed evenly but that wasn't the case. One side of the card is always working harder than the other card constantly and I want to change that by getting possibly 2 gtx 980 TI. So that's my story, ill do a quick summary of my questions.

1. What is the Broadcom 802.11 adapter, what does it do? what are the benefits of having it?

2. Is A11 the latest BIOS? (have had instances were certain newer cards don't work with older bios)

3. What is the dimensions of the Alienware aurora r4 alx GPU Slots?

4. Would the motherboard support 2 980 TI? (does have 2 graphic input but space is limit so that's why I ask)