Why yes, yes it is. There are genes that code the proteins that make up the ribosome for example. The ribosomes in turn interpret the DNA string to make proteins. This leads to a bit of a chicken and egg problem which I mentioned as the issue of bootstrapping. But the DNA does code everything in the cell, or at least defines the machinery needed to make everything.
For example, if executing the DNA instructions produces a human female, she'll be born with a lifetime supply of eggs, the developmental instructions for which were part of her startup DNA. Those instructions were definitely not part of the "cell soup", as is shown by mitochondrial donation assisted reproduction technology (aka 'three-parent babies').
Cells are factories, incredibly complex ones. DNA is a set of punches in a tape.
Not really. The translation machinery is also defined in the DNA. Granted, there is a bootstrapping issue. The chimp argument seemed silly to me. Why not just estimate so fraction of the human genome as defining the brain? In that case 3G base pairs is a bit under one gigabyte of information defining an entire human. Still small in comparison to the quantity of synapses.