Definitely make sure you are allowed to have chickens. Bottom line, though...you should not ever cater to people like this. They are nothing more then miserable bullies. I would also suggest that you NOT babysit for them anymore, and if you cannot help yourself, then inform them what your hourly rates are. Don't cave on this...you mustn't let them use you on top of bullying. Get your composter back, and live your life- I wouldn't even stress until the police ACTUALLY show up at your house. If you are within the boundaries of the law, you have no problem.