The first issue will definitely be fixed with the next update.
As far as the second issue is concerned, I can assure you that the best chromosomes are never discarded. The creatures in the best creatures scene always have the exact same chromosome / brain as the very best creature of the simulated generation. If the creature for some reason behaves significantly worse in the best creatures scene than during the actual simulation, then this is an issue related to something else. (In fact, I thought I had fixed it with this update after spending three days on this bug)
What I'm trying to say is that the algorithm currently properly sorts the creatures and picks the best chromosomes and even if you see that the "best" creatures are standing still, that will not affect the ongoing simulation.
"I had a batch of climbers, one of them fairly quickly climbed up pretty fast and in the next batch it was gone." Do you mean it wasn't in any of the batches of the following generation or it just wasn't in the very next batch of the same generation? (You wrote batch so I'm assuming you were using the "simulate in batches" option)