I've been thinking on this subject recently, the whole am I a Masochist? question.

Firstly The good pain/bad pain thing I do understand, stubbing toe yep ouch, fingernail scratching, nipple clamps, wax good pain.

I think I would come under pain slut as I like my pain in a sexual context but then so do Masochists. If the distinction is whether I then like pain outside of sexual expression that would be an interesting question.
When I got my tattoo I nearly fell asleep I was very 'in the zone' with the constant sting of it, it lulled me into something which was new to me.

I will move away from physical pain a little into the emotional and other stuff.
I have always pushed myself and I have always had a desire to find the limits of things whether that be my physical limits, skills or emotional boundries.

I joked about being an emotional masochist because I have always been the one who got into things and was blind to the falls that were coming but I think that is part of my nature. I don't enjoy emotional pain but there is a part of that which I do understand that may well come under masochism.

The whole power dynamic in D/s to me is as much emotional as it is well power exchange, the rush of adrenylin when you feel that transfer of power and the edge of fear, uncertainty mixed with trust and desire that I love.

So I haven't answered any question but maybe another dimention to it would be the adrenalyn junkie!! I fit that category. I also have some serious sadistic tendencies which don't play out in RL but do in reading/writing and pics I like to explore.

So on both sides I love the helpless sub, I love the pleading. needing and begging eyes. I love pushing boundries and I do get off on pain!

Oh and as an afterthought I do agree, the self whipping thing does nothing for me, that without the power exchange just doesnt work for me where as nipple clamps work regardless. I guess some pain is dependent on the context and some are simply yummy anytime.