Gotta be more descriptive about what you mean by "predictable" unless if you're talking about the obvious Indiana Jones tropes.
Making the character completely stiff is probably the opposite of what you want to do in a animation. You want the character to react from the environment like the character's feather and cape blowing from the wind. It would be rather lazy just tweening the whole thing. Even though it looked a bit choppy I was giving traditional animation a try for the first time though I am guilty of using tweening in some scenes since I need to make the deadline for TOFA.
Are you asking for someone else to write while having flaws? Are you saying get someone else to write because of flaws in the narrative? Not sure if English is your native language. Really not sure what you're trying to tell me here.