yes, but the better question is can your PSU handle the GPU? What size/model PSU do you have? Also see if the GPU will fit into your case because its long.
Sure it does. That motherboard has PCI Express slot and thats it.
Highly doubt it but you wouldn't catch me trying it out.
a good quality 550w will be fine as long as you are not planning on a future crossfire addition.
When shopping for your new PSU besides paying attention to the wattage make sure it has two 6 pin PCI-E connectors for the Radeon HD 6950.