Help with session mode

Hi all,

I have been given some performances to edit and am having a massive brain ache with syncing. Any help would be appreciated!

Info: 3 cameras, no audio on any of them. All started recording at different times at the beginning of the sets. No timecodes on cameras. One camera filmed  (Canon cinecam) for highest res picture - this is to be sped up on timeline to match other cameras. Generally a nightmare. Not filmed with edit in mind.

I need the session mode to start at all different 

I have tried the following:

Creating subclips once I matched all the camera to the audio, so all cameras started from same point. This did not work.

Changing the in points on the clip in the project bin. This also did not work.

I am also not sure I can edit in session mode when one of the cameras needs requires modification (sped up in this case) to match the other cameras? Or can you only use unedited files from in the project bin?

My workaround currently is exporting each clip and bringing back into timeline all starting from same place, at correct speed for playback.

Any help greatly appreciated. I'm losing the will to live.