Change download location of Safari PDF download button I would like the following behaviour of the Safari PDF Download button: 

On clicking the PDF download button by moving the pointer to the bottom of a pdf/ps, the file is downloaded to the Downloads/ folder. Instead, I would like that to work as a "Save As" button so that I can save the pdf by a different name and in a location I prefer. 

I know there is Cmd-S but I would like to use this as an opportunity to learn about Apple Scripts if that kind of idea can be used to solve this problem.
AppleScript on its own can't be used to 'hook' into other actions such as clicking certain things. There are tools available to run AppleScript on keyboard shortcuts, however you might as well use ⌘S in this case, or remap this shortcut with System Preferences → Keyboard. One cannot change the download location of the button in Safari preferences.