That's pretty much the point of most super GPU's - For the pure brag factor (Much like I love to brag about my super internet! )
It will work on any machine. Just you have to have the money. But it is about $250 I think. It is a good powerful chip.
You can't use custom processors for laptops. They are integrated into the laptop's motherboard... that is the only downfall to having a laptop.
Well, in general speaking, you can't change out the processor at all. Dunno where I got the "custom" word from. It's probably from my tiredness... well yeah.
You can change the processor in a laptop. However, judging from the fact that this thread exists, OP doesn't have the required computer/technical skill to reliably replace the processor. If you want a faster processor, you need to get a new computer. Sorry. Also, if you're getting Axolotls, please be prepared for the majority of your spawn to die. (This is a NUMBER, not a PERCENTAGE.)
This is sort of incorrect, you can't change the processor in a MacBook Air. Well you probably can but it would be very expensive and difficult.