>>11. Capable, yes. Obviously you'd have more success with a better processor if your designs are complicated, but it will run it.
1.b CPUs can have what is called Integrated Graphics. This is stuff like Intel HD 2000, Intel HD 3000, Radeon HD 7660D, etc. It's built into the processor. Naturally, while this is convenient and power-efficient, it gives less performance. If a computer has what is called Dedicated Graphics or a dedicated GPU, it has a separate card just for graphics, instead of being built into the CPU. This will be much better at playing games, running CAD, etc. You are correct.
2. It's a new generation of processors that Intel released recently. The 3rd gen is called Ivy Bridge and the 4th gen is called Haswell. It's more power efficient, so longer battery life; it requires lower clock speeds to hit the same performance. If you're buying a laptop, 4th gen would be beneficial. It also has much better integrated graphics, but if you're getting something with a dedicated GPU that wouldn't matter. It's got better performance over-all since it is new.
3. There are many, many laptops available on the market for a very wide range of prices. You can get a laptop that would run AutoCAD for as little as $500, but the performance would be bad. The more you spend, the better you'll run it. You have to ask yourself how much it is worth to you to be able to run this program efficiently.
4. Asus, Toshiba, and Dell are some companies I've had good results from. Asus especially makes quality products, but it will come at a premium since it's from a better-known company. Acer makes very inexpensive laptops, but the quality is apparently more hit-and-miss. However, I've had my current laptop for 2 years, my Dad's had his for 4, and they're both made by Acer. If cost is an issue, I would recommend Acer.
4.b I wouldn't recommend a Mac unless someone had used a piece of software only available on Mac OS for years and couldn't switch over effectively. The hardware is beyond overpriced, it's the software that is valuable.
