I think you are correct about the breathing exercise/ tenaga dalam. I noticed that they cover most planes of movement also (x,y,z). At various points of the set you can see them do the following movements, draw the hands up above head (up), thrust the hands down into the ground (down), lean backwards (back), push palms forward (forward), cross hands over chest (centre) and sweep hand from right to left. It looks to me that they are acknowledging all possible directions of movement whilst at the same time preforming the tenaga dalam.
I dont see any movements that I would consider attacking of defensive so it looks like the reason for the jurus is not martial.
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If you look at this jurus there is only one direction that they did not incorporate. Whilst on the ground a sweeping motion was made with the right hand and it gathered from the right side and drew into the centre. This was not followed up with a gathering from the left. What would be the reason why they may not want to gather the influences from the left?