1) I don’t have a solution for this. Your the first person I’ve ever heard of who uses save boxes this way, so I’m not hopeful you’ll ever see it changed.
2) On a Mac, if I’m in a Finder window and see a file I want to open, I drag the file onto that program on the Dock. I don’t see how copying it and then going to “Open” and pasting it there is anything but a waste of time.
As for the “Save As” trick you have, I suggest just using Spotlight. For example, let’s say you’re looking at your “New York Trip” folder in Finder and you want to save a website there. Rather than copying anything, just go into the save dialog box in Safari and type “New York Trip” into the built-in Spotlight that’s inside the Save window. It’s different, yes, but it seems just as effective to me.
3) Type ‘Flower’ in Spotlight and then pick “Show All” right underneath it. You get a Finder window with your search inside it. In the upper right you see a ‘+’ button. This gives you more ways to narrow the search. Pick “Kind Is” and then “Image” and then “JPEG.”
Then hit ‘+’ again and add a date range or whatever else you want. You can even save your search from there as a Smart Folder which will be constantly updated as your computer changes. Smart Folders are reason alone to use a Mac. If you’re not using them yet, spend some time learning them and they’ll make your life easier.
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So that’s 2 out of 3. You say you’ve got more. Don’t hold back, we’re here to help!