Wedding Footage from beach - fixing over-exposure and colour balance?
What you are trying to do is impossible given how bad the original footage is.  I'm honestly pretty amazed at the result in the third shot given the original state.  Unfortunately, video frames are the equivalent of a series of JPEG images.  It is possible to shoot RAW video on ultra high end cameras, but the data rates are completely off the charts (around 90 to 100MB per second or worse).  The information is simply gone and there is no way to recover it if it was clipped out.

It sucks, but that's the long and short of it.  That's why I always do a pre-roll test prior to filming at weddings, but that's what experience of doing professional wedding videography for 3 to 4 years gets you.