Enough is obviously good, there's plenty of stuff where you need antibiotics to heal. Enough can be bad if abused, since some doctors overprescribe antibiotics for cases where it's not warranted, e.g. a cold. Most colds are viral in any case, so all you're doing is weakening the patient even more. Aside from that there may be severe side-effects, so it's best only to use antibiotics if you know you have a bacterial issue that can be solved with them.

None is preferable to partial treatments, since a partial treatment will create resistant strains and not much else.