Radars pointed at each other may have some interference resulting in temporary erroneous readings but they won't be permanently damaged like the camera in the article.
In a heterogenous environment this is not necessarily true; a radar with a powerful transmitter could damage a radar with a very sensitive receiver, particularly at close ranges.
There are military jamming devices that can quite handily permanently damage radars not designed to distinguish it.
Almost certainly not. The FCC approval process would likely catch that. Lasers are also far more focused then microwaves (typical spot size of a cheapo laser pointer is 12cm at 100m away; police LIDAR is good to target a single car out to at least 1/4 mile).
There are military jamming devices that can quite handily permanently damage radars not designed to distinguish it.