You asked us, "If we share 98 percent of the same DNA with chimpanzees, could you genetically engineer the rest to make it into a human?"
Okay, Dr. Moreau, settle down, we're not making any human-animal hybrids around here, and even if we wanted to, it doesn't mean we can.
See, the important thing to realize is, even though we have 98 percent of the same DNA, it doesn't mean we're 98 percent identical.
Look at a banana, which shares about 50 percent of the same DNA as humans - and you'd never confuse one for the other.
DNA is basically a set of chemical instructions, which tell cells how to make proteins that in turn make us. Little differences in the instructions can make big differences in not just how separate species turn out, but even how members of the same species turn out.
So yes, since humans and chimps share a common ancestor, of course we share a lot of the same DNA instructions - instructions for things like opposable thumbs, no tail, or relying on sight more than smell, not to mention the many, many characteristics we share with all mammals.
We also have big differences. Pound for pound, chimps are stronger, but they can't throw as well. They can communicate simple ideas, but they don't really get pointing. They make tools out of sticks and we make tools that can sequence DNA.
But hopefully, we'll never make a tool to create a human-chimp hybrid. Because both species are remarkable enough on their own.