On the whole "lying at the job interview", I think you have misconceptions about how to do an interview. It's not about saying false things. It's about not emphasizing attributes that are negative. You wanted a short term job. They wanted a long term hire. Don't emphasize that. Don't bring it up. If they ask "are you looking to work here long term", answer with "I want to work. If you hire me, I will give you my best." It's a stupid question for a fast food joint to expect a hire to want to work there long term. NOBODY really wants to flip burgers for a career. But you can't point that out to them, or you'll appear hostile. You also can't say "no." So find a way to say yes, do the job, and quit when a better one appears. Just like everyone else.
I would advise taking a serious look at what folks are saying on getting into writing. You haven't answered the question about your writing experience. Yet, you seem confident that you have a sure deal. That is unwise. There is no sure deal until the check is in your hand, and even then, you need to deposit it.
If you're going to be writing adventures, consider publising them. You will get writing experience, and increase the value of the work you're doing. If you're good enough to get paid to GM, your material ought to be good enough to publish.
If you have no starting capital, avoid doing anything that requires it. Don't borrow books to run games with strangers who might wreck borrowed stuff. Don't get overboard in printing and prop costs. You gotta do stuff on the cheap. A well run game doesn't need tons of stuff, it just needs to be well run, and you can do that off of hand-written notes in a notebook, until you get funds to improve your tools.
I think you already get the point about running a game where the players win. It should appear to be a challenge to the players, but ultimately the players win. There are no losers. This can be hard to do (especially for bad players), but it is in your best interest to deliver ENTERTAINMENT. That doesn't mean a monty haul stupid game. It just means that your careful to make sure the player has a good time. Since D&D isn't a competition, this isn't a violation of its premise.
Keep track of ALL your expenses and income for this business. You won't know if you cross some "need to file" threshold until you cross it, in which case, you'll need everything. Even if it fails, you can claim your expenses for the business, which might help when you get your replacement job later in the tax year.
A good business plan includes an exit strategy. A plan for failure, which includes metrics for signalling failure, and how to shut down the business (selling assets, etc). Only foolish people are against planning for failure, as jinxing their chances. If you have contingencies and failure plans, you have a stronger handle on how to avoid or mitigate them. Failures happen more often than success.
