Here is a list of Advantages and Disadvantages with using The Sims 2 as a game engine to create machinima.
Great characters and custom-ability.
Good models and props for videos.
Lip-synchronization is hard, you have to capture many different pieces of video of a character talking to get good lip synch.
The Sims 2 was made with machinima being the last thing on there mind. The mind set was to expand upon a quite popular trend with The Sims 1. Where people would create stories with the family albums and upload them to the service provided by Maxis. So it was ment more for a bit more cineamatic view on everything and was giving what people belived was lacking.