Short update. My technique is definitely improve, I would dare say a lot.
I still have issue with posture and my managing of proprioceptive information but I've made strides. I think I'm finding "my line" (applies to land too).
I start to enjoy freestyle actually as I only do short length it feels really fast at time. I'm a lot more comfortable breathing on both sides, as somebody posted here I think my left side is indeed cleaner. I've grown well aware about how breathing on one side alter you technique and so the strain on your body (for those that are not built as solid, tough or resilient as others...). I'm holding on doing significant distance and volume at the moment but I still feel like one breath every 3 strokes may be a little to few for me, I may want to stick with a regular pattern that includes more breathing 3/2/2/3/2/2 for example.
Still no luck with the 2 breaths out of three strokes advocated by Gary Hall Sr. May be I will find a way to make it work... one day lol
Other than that along with finding my line I got a better grip on my body rotation. Overall I swimming straighter and my rotation is more symmetrical. Though the rotation "breaks" easier than the line.
As for health well, still hurting here and there, I've to be patient, bad posture for decades took its toll as well as not properly dealt with injury. A focus at the moment is stabilizing the right shoulder, my anatomy lessons comes handy here.
I work on all four strokes, I try not to do breaststroke too much as i realize that it is really tough to resist "the bent or torsion" as large legs muscles engage.
Butterfly is improving I hope for a breakthrough soon.