I have heard of people keeping cherries and chameleons together, and apparently they become quite difficult to tell apart except for the while dorsal stripe. Not sure about CRS, but I expect that they'd be fine too as people keep them with cherries. The only one I've heard people concerned about is CRS and CBS, so hopefully someone with more shrimp experience could give you the lowdown on that combo
I personally wouldn't try with betta. Having tried ghost shrimp and seen them become a tasty snack, I'd say you'd lose a lot of shrimp that way. I have cherries with microrasboras and even then I think they can take out the babies and juveniles without too much hassle. A betta could easily take out an adult. It could be doable if you had a lot of cover and a high population, but I wouldn't start out that way. I'd also go for a betta that is a bit docile, and preferably a bit small to limit the damage to your adult population
You *might* be able to get away with young macro shrimp and bettas, but you should go into it assuming the bettas will be sacrificial. You guys in QLD get M. australiensis as feeder shrimp over summer, so that'd be doable. They are good hunters and they can swim/move forward as opposed to cray who climb and shoot backwards, so as soon as they are big enough to hunt bettas, it would be tricky to prevent it. That being said, they show up as small as glass shrimp, so I'd say you could get several moults out of them before that would be a concern.
Maybe check with Dave at Aquagreen and see if M. bullatum would work for you. I believe they max out a bit smaller so that could be an option in a larger tank.
If you can find them (and if you can, TELL ME!) riffle shrimp would be an option. They are larger shrimp that filter feed, like bamboo shrimp (which I'm pretty sure we can't get here, pity!) so the bettas couldn't eat them and they would have no interest in hunting.