My 2 cents.
- Rapid Task Entry is great if you're working on another program. AND ALSO has a HUGE power : if you paste a list (from a mail, word, whatever), you'll get as many different tasks as the number of lines you've copied.
- Project : every task that have subtask should be consider as a project, in the GTD philosophy.
Personaly, I'v estarted by creating big folders for each areas of my life (work, family, administrative, activities, routines)
Then subfolders for "sub-areas" : things to by, contact related, sport, customers)
Then come projects and "one shot tasks"
I'm not aware of goals, because I don't understand the difference between "monthly goal" and "monthly recurrence", seems redundant.
Using this software is like falling into the secret cavern of REAL PRODUCTIVITY, because you will be able to manipulate, format, check, everthing that is task related, with ease. There is a lot of hiden functionalities that will make your life easier. (drag items from outlook, auto colour task depending on it's content, drag and drop, bulk-change multiple task's attributes, filtering.
MLO won't stuck you into a method, but will be YOUR tool to apply the method that fits best for you.
Now, find a method, thats your first project to set-up in MLO ;-)