Job Search after Graduate Studies

I worked with an M.N.C developing web applications in Java/J2EE related technologies(includes JSF,struts,hibernate etc.) now i quit my job to pursue Graduate Studies in the U.S.A. So I am a student in the middle of my Graduate studies.I had enough of developing mere CRUD applications in J2EE now i want to work in something exciting. The problem is cant say what exactly but i can give you an examples.
Say developing new JDK libraries or writing a kernel for some O.S. or something like that. So I have five questions here.
1) Is it true that people in R & D often use C++ because of higher performance in that case should i consider switching my platform to C/C++.
2) How should i use my time i have one year to graduate to prepare myself for Jobs Interviews for such positions. (e.g. Reading books on Algorithms etc.)
3) How do i know about these jobs and how do i apply to those Jobs.
4) Is it the right time for me to think about Jobs.
5) Am i over ambitious because i am not in a Ivy league, just a normal school. ( My GPA is not so high unfortunately).

Question 1 can be answered by fact, 2-5 are more opinion or relative to your future employer.

1. If you're writing for an OS kernel...you're in the wrong language. Java is way too slow for base systems. You need to be in Assembly and C (not ++).

2. Preparation needs to be hands on. Personally, in school (not for development) I had multiple jobs. People (more often now-a-days) will be more apt to hire experience over education so long as the "experience" isn't older computation.

3. This depends almost entirely on location. Internet has tons of job location services as well as local community should provide some information on that.

4. The only reason you should pursue more education is for more personal advancement. This should translate to higher personal goals which should result in furthering of a career or community involvement. Future jobs should always be on your mind when entering another schooling phase.

5. I think you have this backward. If you're in a normal school with a not-so-high GPA, then your not "over" ambitious at all.