I had a rabbit for my birthday when I was 7 and he died of a heart attack, immediately after chasing the dog round the garden, when I was 19. He never had any vaccinations and never saw a vet.
Basically they thrive on lots of exercise, so seal up all the gaps under fences and let it out in the garden when the weather permits. A reasonable-sized rabbit will fight off any neighbourhood cats - I still have a photo somewhere of mine grappling with the black cat from next door.
Rabbits can stand a lot of cold but not damp. If you put two males together they will fight, possibly to the death, although you can get them neutered. Mine wasn't neutered and was psychopathic towards dogs, cats and people. This may have contributed to his long life - the bad ones always last longer