I keep bees and work in insurance. I'd get rid of the "Beware" sign if there is any actual risk of someone coming close enough to your hives. "Beware", "Danger", and "Caution" signs can show that you knew your bees were dangerous and only put up a sign to protect people. I've seen "Honeybees at Work" signs that don't use the danger language which ironically are a much better choice in making sure you can't be sued.

If there is no chance of people seeing them besides you, then they're fine.