Yup anyone can use CAD, and in fact many do. But to design stuff well, you still need a good engineering sense or knowledge. What we're talking about isn't specifically CAD though, but more CAE (computer aided engineering), more specifically about FEA in this case (finite element analysis) which is used to simulate load on the designed component, to find any areas of high stress. The packages aren't 100% accurate, and it depends how well you mesh the component, but they aren't too far off, and are very useful. Anyway as has been said it's a little more technical then just using CAD blindly to design stuff, so don't let it put you off!
As for T700 and other materials, I have stacks of material data here, if you want to do a manual input I can happily supply the figures. However it could be hard to set-up a MD layup so if you can simply import a T700 MD data as suggested by Roger, I would it would be ideal and should give you better results then using the AS4
