Dropping in a small drop of water it starts sizzling and evaporating immediately, which according to the internet is a sign the pan has reached the right temperature.

I see this online a lot too, but in my experience what you want is the Leidenfrost effect, that means the water will hang for a second or two before evaporating . Some people recommend an infrared thermometer for further consistency, but I personally don't use one.

That being said, I also don't think you should ever heat it all the way up when you're cooking sausages, they necessitate less heat then say steak.

I agree with the comment you got by Joe, you might be trying to flip/move stuff too soon. The food should release naturally from the pan when it's properly seared. Finally are you accounting for the temperature of the food you're putting in? letting it defrost properly and what not?