Re: battery twist switch accident
On a diesel engine (and probably the A4 too) nothing will happen if you disconnect power while the engine is running. The battery is only used at startup to turn over the engine.
The switch needs to be close to the batteries to be practical. You could make a cover for it though. I haven't tried, but I'd guess that a double gang outdoor outlet cover might fit over most battery switches.
1986 Pearson 28-2 "Elena"