#1. You cannot upgrade the graphics in a budget / mainstream laptop.
#2. Only specific gaming laptop models will allow you to upgrade the graphics. These laptops generally cost $1,400+. A gaming laptop that costs $2,000 doesn't necessarily mean you can upgrade the graphics in the future.
#3. See #1 and #2.
Both AMD and Intel sells CPUs (AMD calls 'em APUs) with integrated graphic cores. Intel's graphics cores has come a long way since the era of the GMA 4500HD graphic core, however, many of AMD's graphic cores are a bit more powerful than what Intel has to offer. If you prefer to stay away from AMD for whatever reason, then you are basically looking at Intel's HD 4400 graphics core or perhaps the Intel HD 4600.
Unfortunately, you...