Graphics of that level would cause me to cancel my account. Not because I don't like really nice graphics, but rather because my computer cannot cope with graphics of that quality. My system is more than seven years old and while I would like to have long since replaced it, I cannot afford to do so.
I don't think it would. I am not a programmer nor a graphic artist but redrawing the cockpits to look more realistic shouldn't tax you system any more. Now lighting effects, reflections, and shadows will, but not just the drawing. Please correct me if I am wrong Hitech. I am speaking of purely the artwork, not necessarily the effects.
For instance look at the differences in just the cockpit canopy frames. I can't imagine that canopy frame will tax your system any more than our current version.