Posted by Robert: Most Police officers I know, use a modified form of aikido As thier self defence
They may be taught Aikido-like restraining holds, but I'm not sure I would classify it as "modified Aikido". Many of the techniques are common to various forms of jujitsu/self-defense. Anyway, police have clubs, mace, guns and radios that can get other cops to scene.
Distance has been discussed quite a bit on this thread. I still maintain that you can't count on being able to maintain distance. It is too easily breached and then too difficult to regain.
I agree with your other points though, and in fact I think the attached essay covers the subject in some detail. I don't know much about the techniques that MacYoung teaches, but he makes some great points here: