Well, it is safe to turn a computer on without a RAM, but you can't really do it. RAM is one of the essential components in computers without which you can't really use a computer. You can turn it on, however, nothing will appear on your screen and the system won't boot. So, technically, it is safe, but it won't do anything to your computer as it cannot run without RAM.
The answer is hobby. He does it because he enjoys it. There is no information of him being told or paid to collect bugs, so it is a hobby.
The same thing as if you do it once
