I've gotten sampler of everything and several larger bottles and i'm 100% certain that certain flavors have different ratios. I'd say *roughly* 50/50 depending on flavor, but they will absolutely do a custom on the non sampler bottles.
I'd exercise caution, but I don't think any are known to crack. I had a red ce4 crack around the base with cherry blossom, but I think it was rough treatment vs juice. nothing else has given me issues.