I am finishing off my basement and have started looking at some of my plumbing concerns. I know I need to install drain vents and somehow tie those drain vents into my main vent system. The upstairs plumbing fixtures are walled in so I cannot see any of the drainage pipes. My basement is stubbed in for a bathroom with toilet, sink, and shower. I see what I think might be a vent pipe, but there is not much pipe to work with if I were to tie into it.

So I have a couple questions:
1) Is there a way to tell what pipes are NOT actual waste water drains and which pipe is the one going to the vent? I can see the drains from the upstairs toilet, bathroom sink, and shower. There is another pipe angling up that I believe is a vent pipe, but I want to be sure before I go cutting into it

2) Do I have to tie into the existing vent pipes that lead out through my roof, or can I create a separate vent and just drill it out through the side of my house?