A prodigious offering! Welcome to the still side of things. I'll interpret "suggestions" as C&C, so
1. A nicely composed, moody portrait, but perhaps just a little dark, especially to the RH side. Perhaps a tweak of levels to bring it up about 1/2 stop.
2. Aside from the obvious focus issue, the main subject is a bit dark. A little selective lightening of hair would have helped. As an aside, be careful of taking this sort of photograph without permission. Many stores don't like this.
3. Comments per #1 and an echo of TrickRic's words about backgrounds. I think a little more of the main subjects face would help, and moving a bit more to your left would have eliminated the other person in the picture, who, while not in focus is clear enough to be distracting.
4. Background again, and also the edge of the newspaper box below and left is somewhat distracting. Perhaps clone this out in PP?
5. Nice, well composed, well exposed.
6. A test, 'nuff said.
7. I think either moving closer to the bloom and eliminating more background or a closer crop would help (I would suggest the former rather than the latter). Don't be afraid to have the petals "spilling" out of the frame.
8. A different position would have eliminated the large black area on the LH side, and DoF is a little off, as the bottom centre of the bloom is soft.
9. Again, positioning, and a somewhat soft focus.
10. Nice; a tighter crop might emphasize the spider more.
11. Nice macro, good exposure and composition, again a tighter crop?
12. Background
13. This is a composition issue; which is your main subject, the cone or the flowers? To me, they're fighting each other for attention.
14. Background as well as composition. I would suggest a close crop on the left-half of this picture.
15. Nice, good selective focus, ideal background. A crop to eliminate the spike on LH side is all it needs.
Okay, all of that negativity aside, there's nothing seriously wrong with any of them. Just a few minor things to keep in mind for you next attempt. As for autofocus, use it. It works; just make sure that you have what you want in focus.
All of the preceding has been my $00.02 worth; your opinion may vary.