lturcotte,
Tambi is correct about using complex profiles for what you need. It sounds like you may need a bit more education on the processes and terminology of ArchiCAD.
To save a wall as an Object would remove most of the flexibility of the wall unless you were to program the object yourself with GDL to have more flexibility but this is no simple feat, especially if you are 2 weeks new to ArchiCAD.
Just a point of semantics: An "Object" is a tool unto itself. A "Favorite" is a saved configuration of an object. If you save a Favorite, it is simply saving a configuration of a wall, not a new wall tool. I understand what you meant but I am a stickler for correct terminology as it helps with communication.
A "Composite" is basically a number of skins that can be defined to represent the make-up of a wall, slab or roof. A composite can only be applied along a single axis, so the composite layers will follow the vertical axis of a wall from top to bottom without variation in shape, width, materials, etc. These are great for simple wall construction but top plates and sill plates cannot be included into the composite itself, they would have to be modeled separately if a composite wall were used.
A Complex Profile allows you to create wall (roof and column also) components in any shape and orientation. It is a silhouette of the structure that is stretched across the run of the wall.
Here are links to Graphisoft's training guides:
http://www.graphisoft.com/products/acse2011/ITG/
http://www.graphisoft.com/education/training_guides/
HTH
