Part 1: A lot. Seriously. I got both my BA and MS in Computer Science from the same institution. During my 2-year Masters program, I learned more about computing than in the past four combined. (It didn't hurt that I also got hired as a Unix sysadmin in the department. ;-)

Not only did I pick up specific programming techniques and languages, I also worked with a variety of people. I learned how to cope when I disagreed with someone: either the person giving me direction, or a co-worker.

I have to give a lot of credit to the University: they had a very good program that exposed you both to the theoretical and the practical. In my time there, I learned not only analysis of algorithms, computability, and the like, I also learned a dozen languages, wrote a compiler from scratch, and built a PDP-8 (this was in the '70s). I later tried to continue on to a Ph.D. at a different University, but abandoned it in a couple of years. Not to say the program there wasn't as good, but it just didn't "fit", especially after having worked a few years.

As to Part 2: I don't know. I think it helped in my first 2-3 jobs, but I can't tell you for sure. But after a few years of working, I think it didn't matter. Experience counts much more than education after you've been working a while.