I am trying to remember how I just edited my last two movies I shot with my digital camera and edited on my iPad in iMovie.
Have you just tried looking for the sedtion in iMovie and on the timeline area, take your finger tap once to start tye edit from wherever point you need to start, slide your finger to where ever the end of the edit is to highlight that section,,then hit the delete key ob the keyboard?
For some reason I remember doing something like this when I needed to cut out a section out of the middle of my video because Ieft my camera in record mode and it was recording the ground while I was moving and I needed to delete it out.
I remembered/figured this out.
My last edited video is still being kept inside iMovie on my iPad 2, so I went and did some trial and error to remember what I did
On the timeline double tap on the timeline where you want the edit to start
A series of commands appear. Tap Split to create a split point.
Go to the end of the your edit OR you get cut/edit in smaller chunks, if you like by choosing the Split command, again, to set a split point for the end of your edit.
If you tap anywhere between the Split points you can delete all of frames between the split points off of the timeline.
Not just from the beginning or end.
This was how I was able to do edits in between in iMovie for iOS.
Try it, let me know if this worked for you.
Good Luck!