"Do what thou wilt shall be the whole of the Law.

As so much of this practice is already in a natural accord with the way my mind operates, I am very excited to have come across this exercise in the course of my study.

I'd like to know more about it in regards to prior practices of Yoga. Is there any danger involved with practicing Mahasatipatthana without first having a firm grounding in asana and pranayama? I could be reading into this too much (or altogether incorrectly), and I'm aware this is a Buddhist practice, but I'm seeing similarities between this practice, pratyahara, and dharana.

Really, Mahasatipatthana is so practically relevant to me for so many reasons, I'd like to incorporate it into my asana and pranayama practice in addition to doing it continually throughout the day.

Love is the law, love under will."

93,

Mahasatipatthana is a specific meditation that is aided by a firm foundation in posture and concentration, i.e. asana and dharana. Pranayama is also useful insofar as it is considered rhythmic breath that allows one to concentrate on the task at hand.

It is specifically good to create a sense of 'no ego' through analysis, i.e. using the mind to analyze the 'self' away, leaving only raw perceptions (or the tendency to perceptions, or whatever you are focusing on). Crowley mentions this is useful for K&C insofar as it helps displace the ego.

The only danger I can think of is that you take these meditations as "absolute truth," which is the same danger with all meditations I suppose, but there is a certain utility to the "ego-standpoint" that is therefore equally true (in the pragmatic sense of 'what works best is what is most true') as the "non-ego-standpoint." All things to consider, if you will.

"Is there any danger involved with practicing Mahasatipatthana without first having a firm grounding in asana and pranayama?"

None known to me. It's just a witnessing.

"I could be reading into this too much (or altogether incorrectly), and I'm aware this is a Buddhist practice, but I'm seeing similarities between this practice, pratyahara, and dharana."

It may overlap with them, depending on level. The only "danger," in this sense, though, is of not being able to pay attention, i.e., failure. Not a terribly worrisome risk, since you can easily take it as far as you choose to go.