Hello...
I'll be blunt; Programming can be difficult - very difficult. That said, it's one of the most rewarding things you can do. If you are *totally* new to programming, then that book gives some good advice at the start on how to think and approach problems, if I remember correctly.
A. Yes - very much so. They mend anything that might have been broke with DBP
B. Yes, as with A. Don't worry about dates - just patch it

C. While learning, you won't really need any tools. After a while though, you'll want to use things more advanced than spheres/cubes, at which point you'll need modelling/drawing/leveling software. I suppose we should start a sticky thread titled "free tools", to help newcomers find what they need. I don't know which free tools are worth using tho....
D. It's still useful - you get a feel for the language
I'm not sure about commercially released games...
Enjoy!