In answer to your list, this is what DD could do ... (she is 12 months old now)
press buttons on a toy? Not until about 10 months
reach out for something? Yes
object if a toy is taken away? Only really at about 10 months
clap hands? Yes
wave bye bye? No ... still doesn't at 12 months
look from person to person to see what is going on? Um, don't think so, she only seems to be doing that now ...
turn pages of a book? Not at 8 months, started doing that at around 10/11 months
DS was much quicker at all of this stuff and was crawling at 10 months and cruising furniture at 12 and walking at 14.
DD is making NO effort to crawl, she bumshuffles and is only just beginning (last week) to pull herself onto her knees when holding on to furniture. She is only just beginning to bear weight on her legs when we hold her in a standing position.
At 8 months she seemed really far behind all her little peers as they were all crawling and into everything and she just sat quietly and looked around her. She is making up for it now and has right temper and cheeky sense of humour.
I was worried but then we saw a paediatrician about something else (her skin) and he said, totally unprompted, how refreshing it was to see such a happy, healthy baby who was developing normally as he spends a lot of his time with children with problems. So I stopped worrying ....
All children develop at different rates, I think the mistake many of us make is comparing our babies with others of the same age and what the books tell us our babies should do.
If you are worried Camilla, take your little boy to the HV but I think it is more likely he is just doing things at his own pace ...
HTH ...