
with your permission, I will add my opinion.
Your question could me more complex that it seems.
In China, teachers teach posture by posture and add a new one, only when the first one is more or less known.
Last month a young Chinese girl was in my home. She is studying French and English in a university in Beijing Taiji is a part of her cursus. We have begun to practice the 24 yang form. She has stopped after the first 4 movements and has refused to follow me for the next ones. After 4 months of studying taiji in Beijing, she only knows 4 movments and, of course, she was doing them very well.
In the western world, the teachers teach a whole form, and refine it later.
The question could be : would you be patient enough to learn the Chinese way, or do you prefer the western way or something in-between ?
If it is the Chinese way or something in-between, the question of "how many times" doesn't matter anymore.
If you prefer to study the whole form, it is better to concentrate first on the position.
I think it is too hard for a beginner, and I am a beginner too, to concentrate in the same time on the position and the relaxation.
Maybe could it be possible for a short form, like the 18 form, but not for a long one.
I study taiji for health and martial art too.
I work with the DVD of MAster Tsao and I study 3 DVDs in the same time :
taiji fundamentals for beginners, lao jia yi lu, and martial application of Chen style.
Taiji fundamentals are, of course, fundamentals and many of the exercises explained can be practiced all day long.
For example : do you always keep your shoulders low ? When you eat, walk, drive, watch the tv .... ? I often surprise myself when I go shopping to think "shoulders low".
It is easy to do and no one will notice you are training taiji. If someone notice it, maybe is he also a practitionner.
Your weight must be 2 third on a leg, one third on the other one. When you walk, stand up somewhere, do you respect this position ? Are you aware of it ? Of course, you can stand up 50-50, but from a martial aspect, it will be more easy to push you out of balance.
You do not have to respect the 2 third/1third all the time, but you can train to quickly go from a 50-50 to the right position.
There are a lot of exercises like this in "the taiji fundamentals for beginners".
For lao jia yi lu, I study one lesson at a time and repeat it until I can do it with my eyes closed. You could be very surprised how it is difficult to stay balanced with the eyes closed or to go straight on. (of course, if I do a kick, I do not close my eyes

)
When I am able to do this, I follow the second lesson, and so on.
The martial applications help me to understand why we do some movement or take some position. It is not obvious, when you see "single whip" for the first it has a martial application. By knowing this application (I do not say practice it, but simply have an idea of its purpose) it is more easy to take the right position.
The outer relaxation is not easy to get, the inner relaxation is very difficult, but once again, you can relax your muscles any time, any where, like for your shoulders.
