As a general rule, the least amount of handling for the shortest period of time is the aim for cat handling
cats have very good memories and trust is not transferrable from person to person
body language indicators of a relaxed and happy cat:
coming out of hiding places but not trying to escape
standing up fully
ears up and forward
slow blinking
inquisitive
moving closer to an outstretched hand
coming close to a human instead of hiding
coming down from a high place
rubbing face and sides
a cat in pain will have laterally rotated ears, half-closed eyes, will act passively and will freeze or be tense. May also display eye avoidance, crouch and splay whiskers
osteoarthritic cats will bunny hop up stairs, will angle their body to the side to descend stairs and take breaks. They will be slow to chase moving objects and will hesitate before jumping up or down