Let's take these one at a time:
1. Bad weather. As I mentioned, my set-up dealt splendidly with very large quartering waves, too much wind, etc. The balanced rudder makes all the difference.
2. Cloudy days. Yes, you get less power from a solar array on cloudy days, but with a balanced rudder, the
autopilot doesn't use up much juice at all, so you're still OK.
3. Electrical problems: if you can get 12V to the
autopilot, you are still OK. If you can't, then you probably don't have nav
lights either, so you aren't even legal. The Simrad stick
autopilots seem remarkably robust. I broke one, so I know what it takes, and it takes a lot.
Anything else?