1. Still figuring this out myself, to be honest
2. It's entirely possible, and depending on what kind of "inanimate object" they are, it might even have a chance of working.
3. I'll be entirely honest here: To me, this actually sounds like it would work better than the previous idea. One exsmple comes to mind: GLaDOS. [Portal spoilers beyond this point, but the game is 8 years old by now. Everyone knows that ] She's an AI who has control of the entire facility, so in a way, wouldn't that mean she IS the entire facility? With this in mind, the idea of a tulpa and a wonderland being one and the same makes more sense than one would initially think.
Bonus: That's your decision to make. I hate to give vague answers like that, but the person who knows you best is you. All I can say is that most people who dedicate themselves to it tend to get good results. There is a small handful of notorious "worst-case scenarios (Citation: Search "Koomer," though I wouldn't recommend it to anyone who's just starting out)," but those people were mentally unstable (Not the exaggerated kind of "mentally unstable" like the person above mentioned; I mean legitimate severe mental problems) to begin with. If this doesn't describe you, it's probably fine.
Anyway, I have to go to school now. I hope this helped.