Yeah I've been researching and reading about CRS for the past couple months to attempt to get prepared and yeah, started with the RCS for the past couple months. I will definitely acclimate them slowly and carefully. I've had luck using PlanetInverts method with acclimating shrimp so far, I *definitely* don't want to lose any though, or at least as little as humanly possible :P
So far in this tank I've been doing daily 15-20% water changes with RO/DI water to keep the nitrates down and get the water down to proper specs(for CRS) since I originally used Prime'd tap water(KH/GH:10) to start this tank.
CO2 definitely may have had something to do with the 2 RCS deaths I experienced though, it was either that or yeah, the water i attributed it to earlier; but all the info I can find says CO2 shouldn't affect them at all, assuming you raise it slowly and whatnot which is usually done and what I did. However I haven't had any deaths or any strange behavior since I've been changing the water so that was my reasoning there. idk.
I plan to stay on top of this as I'd like to get all the shrimp to start breeding in here. As of about 2 days ago, all my RCS females are saddled, and all of the RCS in general have been molting regularly and are seemingly pretty happy.
So I believe things are looking up in the shrimp department and I'm hoping it'll stay that way with the CRS. I'll definitely keep your advice in mind, and anyone else's that wants to offer up some info