If I create a currency, and use it regularly in my household between residents in my household, and I agree to let you stay in my household, and let you use my currency, and i let you own stuff in my household at my discretion, and I charge you a fee based on transactions you engage in using my currency in my household, is that theft?

That's basically what governments do.

What if bitcoin charged you a fee for engaging in transactions using bitcoins? Is that theft?