There's a lot confusion about the various titles subs identify as. A large part of this, I'm sure, is that identity isn't always aligned with the status quo; sometimes connotation can really skew what a label means to an individual. A common example would be newbies throwing the term "slave" around because they think it's just the standard term for "anyone submissive," or just because they think it's a sexy term. I feel like the same discussion doesn't happen as often in identifying Dominants. From what I can tell it stems largely from the concept of sadism being a blanket term when it is more of a spectrum. After my last post on sadism, I figured it's fairly easy to break it into four different levels:
Non-sadist - pretty straight forward, these individuals are uninterested in anything sadistic. Even edging someone to the point of frustration may be out of their purview. Generally they may be more interested in geary sex or may only be interested in tying a boy up to get him good and horny before getting him off or fucking him.
Sadomasochist - I realize this term is already in use, but I feel it's better-suited to differentiate from other degrees of sadism. Specifically, under this definition, sadomasochists enjoy inducing pain only in those who directly enjoy the pain. They'll spank a guy or beat his balls as roughly as a guy wants as long as he stays hard or is otherwise clearly enjoying it in the moment, not after. If a bottom stops enjoying it, they stop enjoying it. Sadomasochists are more likely to prefer dynamics where both partners are equals except for who's physically restrained or being subjected to sadism.
Dynamic Sadist - pretty much a sadomasochist that favors unequal dynamics. They usually still enjoy inflicting pain that the sub directly enjoys, but have no problem pushing well past a bottom's level of enjoyment if he fails to live up to his expectations. This is where sadism stops being about the moment and a sadist starts to derive pleasure from the bigger picture that sacrifice can paint. The easiest way to depict this level of sadism would be someone saying "This is going to hurt me more than it'll hurt you." The sadistic pleasure is still there, just not rooted directly in what's happening at that instant.
Absolute Sadist - this is where a sub's direct enjoyment does not matter to the Dom, and as such is also where the lines of consent can seem blurry. Consensual nonconsent as a concept does not exist to some, but even to those it does, lines can get blurred rather easily. Dynamics heavily relying on this level of sadism tend to be less based on fairness, and more on exploitation. Provided that a bottom actually wants to be exploited to that level, it can yield a healthy, consensual, and intense dynamic. An absolute sadist does the things a dynamic sadist would do without direct enjoyment, for no disciplinary reason, probably while sporting a raging hard-on. Anyone discussing play on this level needs to make absolutely sure they do so while clear-headed, as overstating what you can handle can lead to considerable mental trauma.
Using this logic we can attempt to better isolate where different sorts of bottoms fall in the receiving end of this spectrum.
Of course this will vary specifically from bottom to bottom, but the very concept of certain labels may be directly contrary to a given level of sadism. "slave," for instance, would generally indicate the desire to have as few rights and privileges as possible, so a non-sadist would likely be unable to deliver. "boy," on the other hand, is a very amorphous label given staunch differences in the protocol each boy seeks or adheres to, so the term doesn't yield much info on who may be viable tops. On the other end of the spectrum, "bondage bottom" dynamics don't often extend beyond the scene, so they're very unlikely to tolerate or handle absolute sadism given the level of inequality it requires.
Ideally, looking at potential partners through this spectrum should let you ask questions to determine where they stand.