I personally HATE the wait and see option, BUT...8 months is still early to say if there is a developmental issue in these areas...maybe let your HV know your concerns and ask for an appointment every month to discuss this and check on progress??
personally my DS (1st child) didnt roll over till he was 9 months, Sit till he was 10 months, pull up till 11 months, try and walk aided till 14 months and eventually tried walking at 15 months......and NOBODY said this was "of concern".
yes it was "late" but its was not late enough for anyone to be concerned at the time.
He now has borderline dyspraxia, but he also was DX with Nystagmus, a visual imparement, and also had glue ear from a very young age.....all of which could and would have contributed to the delay.
My DD (2nd child) however did everything BANG on time. she was walking for her first birthday, confidently, and is a very energetic 5YO who does gymnastics, cheerleading, dance etc...lol
So basically, dont panic, but dont ignore your gut instincts. Dont be disheartned if people dont listen to you at first, but dont be put off, and make sure your concerns are known.
Hope you understand what i meen....
xxxxxx