YES, A THOUSAND TIMES YES.
YES, A THOUSAND TIMES YES.
At least among life that currently exists, DNA replication is vastly more accurate than that of RNA, so this premise is slightly flawed (see: RNA viruses)
You've obviously never dropped a cat. Simply dropping a cat from, say, five feet will annoy said cat at worst. They can right themselves in a fall of less than a yard, too.
These are intelligent, relatively long-lived animals. At the very least, I don't think it would be crazy to speculate that this one arranged bones in patterns it just liked. The pattern of suckers on it's arms is just an obvious one to emulate, really.
FWIW, the saggy rear windows actually seem to help make the blind spots smaller - my girlfriend's looking to replace her Altima coupe (a sad, sad car) with a Genesis, and removing fear from freeway lane changes is a big plus.
I love 'Shadow out of Time'. As was his way, Lovecraft did a good job with how horribly insane time travel sounds to people who haven't done it.