Could you please explain your workflow in more detail? I am not sure I understand your problem yet.
I import my photos using iPhoto 11 as I use Aperture 3 and/or LR4 to edit events and/or photos.
Into which of these applications do you import your photos? Do you import into iPhoto and then edit in Aperture or Lightroom, or do you import into all of them?
However I am unable to import newer events from the Pictures folder option that Aperture and LR4 gives one to import as all my newer events of the past 12 months do not show up in the Pictures folder.
Are you expecting, that the images that you imported into iPhoto will be stored in the "Pictures" folder, and you want to import them into Aperture as well, or do you want to edit the images that you now have in iPhoto with Aperture?
I think, you may have a misunderstanding how iPhoto and Aperture work. Both are database programs that manage the image files you import. You should not try to access the managed images using the Finder and the folders with the pictures - that is risky, because iPhoto or Aperture may lose track of the image files. If you want to use an external editor to edit the imported images, use iPhoto's or Aperture's interface to external editors.
To switch between Aperture and iPhoto is very easy. Both programs can open each other's photo libraries. To edit the events that you imported into iPhoto with Aperture, simply open the iPhoto library with Aperture.
In iPhoto use the command "File > Open Library in Aperture"; to switch back to iPhoto use Aperture's command "File > Open Library in iPhoto".
Some things to consider, when switching between Aperture and iPhoto:
Aperture 3.3: Using a unified photo library with iPhoto and Aperture
Regards
Léonie