colgate_girl:
Judging by the amount of interactivity that you want in your game, the easiest thing for you to do would be as follows:

1> Create the characters that will be in the game (who they are, what they look like)
2> Create the story line(s) that will be in the game
3> Create the scenes' backgrounds in Poser (or any other art program that you would like to use)

If different different characters can be used in the same scene (I.E. Either Joe or Jane can be the bartender in the bar scene):
4a> Create the characters in Poser and create every animation that the character is capable of (walking, fidgeting, dancing, talking) on a background color that you won't use on characters (fuschia #FF00FF (255,0,255) works well). This color will be used later on to specify transparency for your animated sprite.
4b> Save out each animation for each character separately
5a> Create and render all interactive objects in the game, with all applicable animation sequences, following the same procedure as 4a & 4b above

If all player animations are hard-coded in a scene (I.E.: Only Joe will be the bartender in the bar scene)
4a> Create the characters in Poser
4b> Create the interactive objects
4c> Import the characters and objects into the scene (if it is a 3d scene) or import the scene image (if the scene is a 2d image) and then animate the characters and objects
5> render out each animation sequence

Once you have created your game content, you need to either code your own engine (C++ or Java or VB or what not), or use a program such as Director to implement your branching storyboard. For something with so much stock footage, your best bet for efficiency would be to use Director or a comparable program. If one of your goals with this game is to develop advanced programming skills, go ahead and code your own engine for manipulating the bitmaps and animations.

I hope this helps you, and I hope it also shows you just how much work is involved in making an interactive game.

mr_sanity