You can get shingles again.

Yes, shingles is reactivation of latent herpes zoster (chickenpox) usually acquired in childhood. The vaccine prevents these reactivations You can have shingles multiple times, and some people are more prone to recurrences.

Clearly it doesn't, given that semidetached just said he took the vaccine and then within months got shingles.

One counter example does not disprove the substantial studies that show a strong percentage of cases that are avoided.

He also stated that he had a mild case. Trust me, shingles can be extremely unpleasant. Any level of protection from the vaccine is worthwhile.

Yes. Risk of Shingles doesn't decrease after an outbreak (sadly).