crs was a mutation of cbs. Now if you just buy one or the other (crs/cbs) they'll throw both, unless you have a pure line.
May as well just start with TB x TB. They are cheap enough now.
Welcome! Great to have you here.
"start from the very beginning of bee shrimp and hopefully get some Taiwan bee shrimp"
TB are a mutation, and you'd wait a very long time to get them from crs/cbs.
Culls are how I have gotten most of my projects. It's true that wilds occur, however sometimes some interesting colors pop out due to recessives/combo genes.
I know you can use epsom salt for adding gh for fish water. According to my notes "1ml per 10 liters= 70 mg/L CaCO3" So 70ppm/17.8 = ~4gh if my math is correct
Never tried it in a shrimp tank though.