Don't fret too much.
Employment prospects for newbie FI's are very good at the moment. Look in the back of this months flyer/today's pilot mags and you will see four schools crying out for FI's. Most schools seem to prefer newbie FI's as they can then be moulded to teach the way that the CFI wants things done.
Whether a school wants full/part time is really dependent on the school in question. A small local club may only need someone to fill in at the weekends doing trail flights to take the pressure off the full time instructors and a large school will only deal with full time employees. If you are targetting a particular school, go along and chat to the instructors to find out how best to present yourself to the CFI.
Don't worry about your experience level . I would bet that 98% of instructors today started out with a freshly minted CPL and 240 hours in their logbook. In the current market there is a shortage of instructors from PPL up to the top echelons and you should breeze quite easily into a job, whatever you choose.