Lidar systems are all going to be some wavelength of infrared, which means there isn't going to be a visible light component on the ground and, conversely, no amount of visible light emitted from the ground is really going to have any impact on your drone.
Specifically to your question, a visible laser being shot from the ground should have virtually no effect on the lidar unit. It might be possible to get an IR laser, but if that's the case then you're already dealing with someone more advanced than your run-of-the-mill vandal.
Once someone gets an IR laser, they'll then also need to be capable of spotting it in order to be able to target the drone. I've got first-hand experience trying to spot the lidar output from about 20 meters and I can tell you it's very difficult even with night-vision goggles, a dim viewing area, and knowing where the spot should be.
This means also that whoever is targeting your drone is going to need some very sophisticated IR/night vision equipment to spot the infrared laser from whatever distance you're going to be flying. Again, even at 20 meters, which isn't really that high, the laser spot is going to be very difficult to see, and again also they'll only really be able to interfere with your system at night.
So, from that end, I wouldn't really worry about someone being able interfere with drone.
Regarding your other points, yeah, the lidar needs the emitted laser light to be reflected back at the unit, so you're going to have difficulty measuring highly reflective surfaces and highly absorbent surfaces.
Finally, I would not be as concerned with the platform vibration affecting the scanner as the other way around - the lidar units have a spinning head inside that turns typically at 10-25 Hz or so, which means basically you're going to wind up rigidly coupling a gyroscope to your airframe. You may find this degrades your ability to control the quadcopter. You could of course get around this by using a solid-state lidar, but I've worked with quite a few lidar companies (SICK, Velodyne, Quanergy, Ouster) and nobody has even a demo unit for us to evaluate.