I just wanted to thank everyone for posting in here. It gave me some great ideas and I've been trying it out. I think I may be starting to get the hang of it. :)
Ironically, I found this article a few days ago which also happened to answer many of my questions and taught me a little bit to use it better:
http://tidbits.com/article/14478
I figured it may come in handy for some others here. It's not only a great review, but also describes the wonderful features of OmniOutliner. I hope you all find it as useful as I did. :)