I agree to most of what you say besides this
"Read up on osmotic pressure and osmoregulation specially for inverts. TDS has more to do with success in keeping shrimp than pH"
PH is huge! Especially with Tigers, CRS/CBS and Taiwan bees. Too high or to low could be the difference in living let alone breeding
I agree and disagree. lol. I think a lot of shrimp have become a lot more hardy in the past few years and breeders all over the world keep them in a variety of conditions. I've spoken with a few breeders in places like eastern europe where active substrate is almost non-existent, and while their tap water is very pure, or they have RO it's a high pH. They will have like 1 active substrate tank to make a low pH water from, import crs/tb/tigers, whatever from Germany/Japan/Taiwan that come from a low pH tank and spend 6 months acclimating them to a higher pH yet same mineral content and have crs/tigers and even TB's breeding in a 8pH water yet everything else is the same mineral wise. Is this for the light hearted? No. a 6 month acclimation of careful mixing of waters to know exactly how the pH will increase each water change and keeping it consistent is hard, yet they do it out of necessity. Once done though, they have a line of shrimp that is used to that water. The biggest part is getting babies born. As Liam even said a little while ago, shrimp born in a water outside their range are much better adapted to that water.
There are more and more stories of people keeping and breeding CRS in tap water or water with params with that the "norm" says they HAVE to be. There is a member of my local shrimp club who has a 5gal bare bottom tank with tap water and CRS breeding in it. Not the greatest baby yields, but those babies will probably have better yields and their babies better yields. A few years ago there was a member on our local aquarium forum who did the same thing and was selling just pure tap water CRS that were breeding hardy and like crazy that he was selling them and selling out all the time.
When I moved an adult population of neo's to my crs tank, from 8pH to 5pH, did they all die. Yup. When I moved a clump of moss full of new born neo's from a 8pH tank to a 5pH tank, did they live. Yup. The babies were probably only a few hours old and I just grabbed a huge handful of moss and moved it and they grew up fine in the water as they didn't know any better.
I've already moved my CRS stock from a 5pH water to a 7pH water and breeding is out of control, babies everywhere, berries almost back to back. Am I going to try and setup a small tank and do a long acclimation to my 8pH tap water with some of that stock. Yup.
Two years ago we were told TB's needed like a 5pH water and maybe at that time they did. Now they are as hardy as CRS and people are keeping them in a 6.5-6.8 water with breeding.
Is it better to match the params of the shrimp keepers who you're getting from? Yes.
Do shrimp do better in the general conditions usually given? Yes.
Are these hard fast rules that have to be followed and any deviation from that will result in death? No
Is active substrate/low ph usually the best for beginners keeping crs/tb. Yes
Is there exceptions to the norm and can those norms be broken. Yes
I always love/hate threads like this because it opens up great debate that challenges the norm, but I always try and caution new keepers that it may not be the best way to go. I tried to stress that in my thread/journal about not using active substrate anymore, don't dump $500 worth of shrimp in a tank like I did and blame me if it goes wrong. I took the risk, did my best for a very slow acclimation into a very cycled 3 month old tank and am having good success but as with anything, YMMV and sticking with the norm for beginners is the best place to start, but it's not the end all-be all of keeping.