This is the solution I am using for fast small improvisation
I create a new Aperture production library for each new project. I don't want to mess up the originals. I import all necessary videos and pictures to the new production Aperture library and then syncronise that production library through iTunes: clean and simple! Sometimes the syncronisation has some problems but then you just need to close your Aperture and close your iTunes. The syncronisation does not look to work most reliably that is a bit painful. To circumvent the syncronisation problem: the Time Capsule may be a solution -- as suggested here.
Analysis
Community wiki answer where I am documenting solutions. Bruno here provided the solution fastest for finding the files in Quora but I am not able to get them into iTunes. I don't know yet how to syncronize things over OSX and iPhone now easiest, testing.
0. Create iMovie projects in OS X and iOS that you synchronise -question
I. Finding video files (found in MTS format)
Go to the AVCHD file (that is actually a folder)
- click "Show Package Content"

click "Show Package Content" again with something called B
now the videos are *MTS files. Enjoy!

II. How to get MTS files to iPhone?
MTS files do not work directly in iPhone. So you cannot transfer them just like that from the STREAM/*.MTS to DropBox and open in iPhone.
III. How can I get the videos from the camera to iTunes and sync to iPhone? Drag and dropping does not work from the video view to iTunes.

IV. How to get the videos easiest to iPhone from the Sony camera?
I don't know the answer yet.
V. How to get the videos easiest to OSX from the Sony camera and iPhone?
I don't know the answer yet.