it is going to be real laggy, i know that i can't make any HD content it would just be used to edit some video projects for my work, because i have final cut pro on my mac pro at my job and it runs crazy fast.
I can't make any promises. I know that Aperture simply refuses to run at all on computers that fail to meet the requirements. The installer will give you an error. It's possible to hack the installer to run on a computer with less memory than the minimum requirement, but not the graphics card.