If you don’t upset the neighbours, they’re unlikely to shop you. The council are unlikely to take much of an interest either, as long as you don’t do anything to annoy them of course. Their problem is that in most rustic areas this has been a long standing cottage industry, and forcing the landlords to comply with the EU safety rules and pay taxes will basically shut the industry down – meaning an end to any local tourism.
As a newcomer, however, your position is very delicate and I wouldn’t recommend anyone to start doing B&B if they NEED the income to maintain their property and standard of living. The other big risk is if a guest has a bad accident and sues you – if you weren’t complying with the safety regulations you will probably lose your house and possibly even end up in jail.