Not too bad. In strict German it would be "Die Achterlieksverklicker sind absorbiert." I am sure that normal german people wouldn't understand it.

It depends a bit on the boat and point of sail.
First some numbers:
alpha, cL, L/D, % sep
10, 1.23, 65, 100
12, 1.33, 50, 90
15, 1.38, 28, 60
18, 1.33, 14, 40
The first number is the angle between wind and sail (angle of attack). The second number is the lift (cL) of the sail, the third number the lift to drag ratio and the last one is about the point where the flow stalls (0% is the mast, 100% the leech).
While beating with fast boats cL and L/D are important, but with stronger wind cL is less important. The higher L/D the better the vmg. For only a bit more cL you pay with a lot of drag and you will be slow. On all other courses, cL is relevant and you can forget about L/D.
Going upwind, leech tell tales are very useful. Going downwind without spi, tell tales at 60% at the leeward side of the sail are useful. With spi, the main is tight anyway and you control the heel with the traveller (or main).
Tell tales at 30% on the windward side are useful to find the right angle of attack.
The numbers above are from a aircraft airfoil, they will be different to a sail, mainly in terms of drag, and they include only what we call profile drag. But overall effect will be the same.

Cheers,

Klaus