Hey Gavin --
You may want to repost this in the Dramatica section of the forums rather than under "Forum Guidelines and Policies." Just a thought.
Now to your question.
Do not expect to learn all of Dramatica at once and apply everything to your script. Learning Dramatica takes time...lots of it. BUT -- you do not have to learn much to get value out of Dramatica. Here are the things I think are most important, somewhat ordered by their importance to fixing story problems:
The Four Throughlines: Knowing what the four throughlines are in general is probably the single biggest problem-solver for most scripts. Many scripts fail because they do not have all four throughlines.
The Main Character need not be the Protagonist: Understanding the difference between the personal throughline of the Main Character and the function of a Protagonist in the Overall Story throughline frees you from creating cookie cutter heroes.
The Main Character can Change OR Remain Steadfast: Though all characters should grow, Steadfast MC's grow INTO their resolve, while Change MC's grow OUT OF their resolve.
The Impact Character is NECESSARY for the Main Character to Grow: Without the intended, or unintended, influence of the Impact Character, a Main Character will not grow.
The Eight Dynamic Questions: These eight questions control the emotional sense of your story's message. They can be used in any combination you want. Each combination gives the story a different sense of meaning in the broadest aspects of your message to your audience.
The Eight Objective Character Archetypes: Knowing the 8 archetypes gives you a place to begin populating your story with characters that have specific functions in the Overall Story throughline. Understand that archetypes are like characters with training wheels -- they are oversimplified but a good place to start. Turn them into complex characters to make them seem more real.
The Four Domains: Knowing that the four domains (Situation, Activity, Fixed Attitude, and Manipulation/Psychology) are the broadest areas of conflict, and tying the domains to the throughlines begins to lead a writer's thinking about how his story should develop. This is the only item on this list that seriously benefits from using the Dramatica Pro software, but you can work with the concept without the software.
Both the Dramatic theory and the Dramatica Pro software have a LOT more going on in them than the list above, but those are the concepts I think are most useful to those new to Dramatica.