This post is just soo sooooo ripe for sarcasm! It's hard to believe you've painted yourself as such a large target.

If you want to develop the hardware and software required to convert the commands from a TiVo remote into commands for something else, well, enjoy the learning! Part of the learning you'll be doing will have to do with the nature of doing something by yourself, for yourself, and the astoundingly large amount of time it will take. Your reward for this astounding amount of spent time will be a remote control. I am now going to take a moment to say this: Whoopee!

I hardly think it will be worth the effort if the goal is to do what you say. If you change the goal to "what will I learn about remotes, software, and the behavior of people who beat you down when you have an original idea [that they judge to be a waste of time]," then you will be educated indeed.

By the way, I've seen projects such as this called science projects or art projects, because like those kinds of things, you won't have any idea how much time it will take, how much it will cost, or even whether it's possible with the skill you have and the unknowns you don't have.

TL; DR: Yes, crazy.