@testo - I'll try to answer your questions point by point:
1. When operating at it's max measurement rate of 1000 samples/second, and scanning at 3Hz, you get around 333 points per revolution, or 1.08 degree angular resolution. You may find that it's better to run it at 4 or 5Hz and get less angular resolution if you're moving more quickly.
2. Sweep's range depends on several factors, including the surface characteristics of the material it's looking at. Even when operating at 1000Hz, it can see surfaces up to 40 meters away, though it will be a little less accurate then when running at 500Hz. Sweep does do a better job of detecting black objects compared to other LiDARs, but they still can be harder to see.
All this information is also contained in our User's Manual.
Good luck with your project!