>Running is actually good for your joints.

Running a reasonable amount (contextually defined), with good form, in appropriate footwear, ideally not on hard surfaces (i.e. concrete) can be good for your joints.

Just about anything done with poor form or in excess is going to cause issues. Not sure it's a useful point.

Depends on age. If you are under 40 running can be beneficial for joints. Especially if you start running at later age then it could cause problems.