Regarding laundry list of jobs: I dont think there is anything wrong in determining what I feel is the best suited job for me (based on my current self (mis-)appreciation. Plus never have I stated in my post that I am Good enough to become a Google Engineer or FB Engineer. [I just mention it is really hard]
Finally Open Source is a good alternative to display your capabilities. But the fields in which I currently work [Machine Learning/Data Mining], writing a correct code is just a primary and non-significant step. While coming up with a novel algorithms is considered as a significant contribution.
I recently tried implementing an algorithm which I felt was interesting in my favorite language and distributed on git-hub. however I still felt [note I might be incorrect] that this sort of work was not valuable enough in my area of interest [again not expertise to be humble]. I can try to show my programming skill via my grades. But Open Source isn't that much important in my case.
Thanks again for your views