I would echo what Kimmy said. You should make yourself go out and do it for 1 week then decide if you want to continue. All groups are different. I love my masters group but we're on a hiatus right now while the pool is getting maintainence.

As for the different strokes, I like Kimmy's approach. It is good to try the others. Backstroke helps to each some of the aspects of roll and body position in the water and that translates to a faster freestyle. Butterfly really works your catch at the top of the stroke and your abs, also good for your freestyle and breast stroke improves your pull through the top half of the stroke. But you also don't want to wreck your season by doing butterfly when you might be hurting your shoulder.