A) I highly doubt it. When I was a flight instructor, I was single, lived with a couple other people (less rent), had no big expenses like a car payment, and I could barely afford to live. If you are willing to have a 2nd part time job, and your wife is willing to also have a part time job, and assuming you don't have a lot of debt (car payments?), then yes it is possible. It will be very hard but we all went through it. Hopefully, you don't have kids because that would make it virtually impossible.
B) Very unlikely. Most flight schools don't give their instructors any benefits (not even health insurance). Even the large aviation universities probably don't give their instructors benefits. In fact, some flight schools only hire you on as a contractor, instead of an employee, so that it is easier for them to tell you "we no longer need your services" (i.e. it's easier to fire you). If you want health insurance, you will probably have to either get it from your wife's job or pay for it yourself. Unfortunately, lots of instructors go without health insurance because they can't afford it.
C) Sure... if you are willing to fly full-time. You can certainly go from 0 hours to working as an instructor in under 6 months if you don't have a job and can basically fly 7 days a week. Contrary to what many pilots might think, flying a plane is not rocket science. Almost anybody can learn how to do it well enough to do it for a living. If you are a quick learner and a hard worker, you can certainly do it in 6 months. Can you afford to not work for 6 months?
BTW, I hope you have a college degree. You'll need one in order to make it as a professional pilot.
Also, $12,000 (USD) is not nearly enough to pay for your flying expenses. Count on doubling that, at a minimum, to take you from 0 hours to a flight instructor.
Good luck. Remember, don't throw everything away just so you can fly planes for a living. It's just a job after all.