answer 1: is yes python is installed
Python 2.4.3
Python 2.7.1
Python 3.2
are supported
answer 2: A lot of python libraries are installed, check out Snake Charmer . For what isn't, like say I use haystack and whoosh for search functionallity. I simply include the module in my project directory.
And answer3: Full support for Django 1.3 and 1.1, and you can use Django like any other python module like in answer 2.
I highly recommend reading Django Docs for more info on Django and how to use.