Yes, you can use an 8GB SSD with 3x2GB DDR3 1333MHz RAM.
Yes, you can use an 8GB SSD with 3x2GB DDR3 1333MHz RAM.
Yes, this setup should function well. I've used 2x4GB plus 1x8GB DDR3 for many years without any problems, and I've also tested other unusual DDR2 setups.