My signature says it all.
Shrimp need a well-established, mature tank. Wait until your tank has been cycled for a month or so. I learned the hard way about introducing them too soon and watched them kick off one-by-one.
RCS are hardier than CRS. Any of the Neocaridina are easier and more forgiving than the Crystal Reds. Amano Shrimp are larger and quite the characters. I've seen mine back down a Betta who got too close to their algae tabs. They are only colorful in personality.
Ghost/Glass shrimp are "feeders" and not given the best care before they get to the lfs so deaths may have nothing to do with your care of them.
Hope this helps. I love my shrimp and other inverts. All live with my Bettas with no problems other than the occasional short chase.