Pointing to things - I think Moo was just under one and it started with using his entire hand instead of one finger
Make animal sounds - doesn't do this and he is over 2 years old
Mimicking me - just started this in the last couple of weeks
Say single words - can't recall his age but I guess it was between 12 - 18 months, stuff like dog, mumma, dadda, ta. He's not a huge talker now either
Stacking things - probably around 18 months, before this he preferred to just knock things down!
Taking off their clothes - in the last few months he's been taking off his pants and nappy at bath time, other than this he has no interest
Getting their shoes - around 20 months

You know your child better than anyone, I hope all is well with him. I know my MCHN has expressed concern over Moo once or twice but he's not a performer and doesn't do what a strange lady asks It might help if you wrote down what he is doing though, you might find he is doing other things instead. For example my little guy wasn't into stacking but was very quick with the puzzles and shape sorter!