Fair warning: I'm pretty casual about stuff like that. Years ago when I had only one bike, an old Trek tourer, I swapped three sets of wheels (with cassettes) and used it for touring, fast group rides and as a cyclocross/pseudo-mountain bike for a couple of years. It had horizontal dropouts, so I could just slide the wheel back and forth for chain tension. And it used friction shifting, so indexing wasn't an issue. Never had any problems.