Bondage doesn't necessarily hurt; done well, it won't hurt at all (unless you want it to). Think of a snug pair of gloves; restrictive, a definite feeling of something there, but not painful.
Some people do enjoy some pain. But don't assume that wanting to be tied up means you have to want to be whipped! Some people prefer tickling, the feel of "force", or just the constrictive feel. Even for those into pain, bondage itself shouldn't be overly painful: it should be more along the lines of a hard yoga class, not medieval torture (no matter what the porn stars act out). Some ache, some stretch, but not real pain. For that, use the whips -- floggers and crops can give a lot more sting without the risk of tearing joints.
Most subs indicate to me that yes, gags do hurt after being worn for awhile; but again, this isn't tearing, screaming pain, it's muscle ache.
"Everything else" is a huge category...and not the same for all people. For instance, anal is torture for some people, and others never have a problem; pony harness is just clothing, nipple clamps can be fairly intense: the list goes on. An important thing to keep in mind is that sadism/masochism (enjoying painful eroticism) is only one aspect of BDSM/kink.
And ultimately, the goal even in sadism/masochism is not PAIN -- it's pleasure. If you haven't experienced, on some level, that pain can be pleasurable, S & M isn't for you -- and that's perfectly okay (there's still a whole wonderful world of kink out there, ropes and chains and all).
As for finding a Dom...don't take it too seriously. Doms are just normal people who happen to like kinky sex. Find a good one the way you'd find any potential partner: build trust, build understanding, and then move forward with the rest.