Great image ... so dance is a kindof whole body version of Joe Cocker-esque spontaneous air guitar, the unconscious air-drumming of the body, literally embodying the beat. I dunno if that's a liberating or imprisoning idea ... a dancefloor of twitching marionettes!!
I think it's kinda both... There's always that balance in arts/music/dance/well everything, between the rules and laws that define the parameters of a self-contained world*, and the areas where there's room for infinite variation. That balance of form and chaos. If these definitive rules are changed enough it becomes a new form. I guess the freedom is in the variables (you can't drive off the road but you can take it anywhere you want**...); or in saying "fuck it" and ignoring the more arbitrary laws, in effect setting new ones, (usually not always
that much of a deviation from the last set.. unless that's the point), or trying to create new spaces with looser or no parameters (a worthy cause that I'm interested in, though I think the latter is likely impossible, and not necessarily a good idea... the distinctive "laws" that define and separate things, if not too strict or limited, can be what make them interesting, but getting stuck in, or conservative about them is boring)...
*some laws are unique to a form, others are almost Pythagorean laws that transcend genre/culture/etc, like say, in music; staying in time (everyone can't just play in different tempos, unless you're the Shaggs), being in tune (unless it's atonal or microtonal, but then that would still be the fact of, and therefore the rules and parameters of, that form), harmonic laws (unless it's a form that allows you to go "outside," like in some jazz, jungle, noise etc, or if it's modal, having no harmony save incidental moments when countermelodies or lines harmonize in passing), etc...
**or, related to your original statement, tho dancing to a set beat, there's freedom and infinite possibilities in your interpretation