Hey subvention, "La Perouse" has some stunning photographic options, maybe explore away from the crowds.
As others have said, first image lacks a focal point.
2nd image, does have a focal point of the watchtower, but composition could be better.
Walsh bay, for me is about the beauty of the old wharfs. Which could be offset against the NEW building skyline of North Sydney.
The picture of the tug boats, is underexposed but could be cleaned up via pp. Unfortunately its not an image that grabs my attention.
The little girl on the cliff top rock formation, certainly has merit, but the subject is too distant to provide detail if she was infact the focus as previously mentioned.
I'm based in Sydney, hit me up anytime if your interested in exploring out and about. I prefer sunset/night time around the city.
And as some old wise guy said to me, "Keep taking pictures, its like anything, the more you do, the more you get better at it!"