Mayank,
First, thank you very much for following our posting guidelines and providing so much information in your post. By doing that, you’ve enabled me to answer your question on the first try.
You’re experiencing problems because you don’t have a full version of Eclipse installed. You’ve most likely got just a platform build, which lacks the development tooling, or a JDT build that lacks the PDE tooling. In any case, you’ll need to uninstall MyEclipse and Eclipse and then download and install the complete Eclipse M2 Eclipse distribution. Version 3.6.1 will on M2, but the upcoming service release 3.6.2 will soon be available for M3. For all production work, we still recommend the use of Eclipse 2.1.1 due to its proven stability.
–Scott
MyEclipse Support