do not get discouraged. get a car, just do not have accidents
seriously, most that people get here is small stuff: dents, scratches, bumps. i would not drive without the insurance but most people here (dominicans and gringos alike) do not have any and they do not care. heck, many dominicans do not even have a licence
on the other hand i have heard many times it is not good to leave the car for a long periods of time without using it. not to mention security - you will be away for months at a time. scooter? man, i don't know. if you do not plan travelling a lot you'd be better off using taxis and public transport. getting around the north coast is cheap and easy.
when it comes to the household items you may check dr1 ads. some folks move out and sell their stuff. local papers for gringos also have advertisement sections. sosua or cabarete have garage sales so you may find good offers.