Hi Manita,
I must say I don't like any picture here, there is something in every picture that nags at me. I think for me, there is no discount when it comes to age and pictures, though I acknowledge that you are doing reasonably well given that factor. I think one general comment would be that for some of the pictures, the sky is way too dark. I'm not too anal about having a nice shade of blue, but pitch black can lead to a "floating disembodied lights" effect which can be rather undesirable.
Going into detailed comments:
#1 - far too much dead space at both top and bottom. This might be better suited for a panoramic crop, but even then the gently upwards sloping "horizon" (inverted commas because it's not the true horizon, which means your shot can be level but still end up having the perceived slant - this is because of the bank coming towards you or away from you, giving such an impression) as well as the huge hot white flower on the right end up making this a rather weak composition with the primary focus shoved in a corner.
#2 - Interesting way of presenting it. Still, the angle of this building is not really desirable to me. Understand that these lights only come off after dark most times of the year, but this is really not a very photogenic view of MBS. Perhaps try it from somewhere more to the left relative to the MBS (Collyer Quay is one choice, from Merlion Park is another)?
#3 - I'm never really a fan of selective color, because to me, it is a tool overused with little positive purpose. The red stands out here, that's for sure, but that's generally the idea of selective color. Putting a possible bias aside, the rose cuts across the silhouettes of the boardwalk as well as the light bokeh - would it be better from a higher/lower perspective to avoid mashing everything together? Also, a tighter crop discarding the right side of the picture seems better for me - perhaps square, or 7x6.
#4 - It's an ok study into symmetry, and the shadow provides a not-so-strong-but-alright lead in into Parliament House. Still, I would crop off the sides (to mantain symmetry) - main reason is the Shenton Way building at the corner that is standing out way too much.
#5 - The sky is nice, and this is a better timing than most of the other pictures. The extremely distorted MBS really spoils this one for me, it's over-domineering as a result and thus grabs all the attention, while not looking really good as well.
#6 - Composition is good for me, but this pitch black sky is really resulting in a mess of blackish details - I suppose you could discern it, but an earlier timing would have really helped. In addition, Alkaff Bridge is really colorful - so an earlier timing might help to make it stand out even more from the back.