Originally Posted by liolio
As much as I want to learn butterfly, I think I will have to stall my efforts at the moments, it is simply too easy to inadvertently try to force through the stroke and even on short distance I think it might hinder the efforts I have to do to stabilize my shoulder blade and matching muscles => I'm going to work whole body dolphin and dolphin kick and so "cobra" type of breaststroke in the mean time.
I think you are right that one of the difficult things to learn in butterfly is to use your whole body in unison with your arms, as opposed to relying too much just on your arm stroke. But, if you have enough time in the pool, I think playing around with butterfly can be a lot of fun and it may even help your freestyle. If you are worried about stabilizing your shoulder blades, I would suggest the following dry land exercises, called I,Y,T, and W
I learned these in physical therapy when I reached the point where the butterfly recovery was hurting my right shoulder due to an old injury. I now do them on both shoulders and I have no problems with the butterfly recovery.
I think that there are two different approaches to learning to breath easily in freestyle. The first is to learn to balance your head over an extended shoulder on your lungs. This will support your head as you rotate to breath, and you won't need to lift your head in order to do so. One drill that helps to learn this is rolling to breath while skating. The second approach is to incorporate a very small amount of body dolphin into your freestyle. By timing your breathing with the undulation of your body dolphin, the breathing becomes much easier. One way to learn this technique is to do one-armed freestyle with the other arm extended at your hip.
Both of these approaches can be used together to varying extents, depending on your body density and swimming style. The asymmetric loping style of many elite swimmers uses this type of body dolphin, which can also be used to enhance the propulsion of your arm stroke.
But all of these different techniques take time to learn. Just like swimming different strokes, it can be fun and useful to learn both of the above techniques. Lots of stuff to play around with, but these can be challenging exercises. Don't expect immediate success with them. If you get frustrated, go on to other things and come back to them every once in a while just to see how you are doing. As your technique progresses, you will notice it in your ability to do these drills.