You've likely already noticed these CMOS cameras really like a whole lotta light.
A lot of it!
Don't ever starve your sensor for light, not that you have here, but just going forward.
Observations of mine are that in this pair of shorts (and I understand the difference between them) is that there appear to be four different styles in them: hand held, tripod, quirk shot, and skaky cam.
Hand held: watch some Terrence Malick, especially 'The New World' and 'Tree of Life'
http://www.imdb.com/name/nm0000517/?ref_=tt_ov_dr
Tripod: watch 'Contagion', and... have your horizon lines off-level with a purpose.
In fact, mixing the off-level tripod shots with the quirk shots (the dorky centered box shots) kinda mixes up the mood in a kind of ketchup on ice cream sort of way.
Qu!rk sh0ts: you know. the 0nes that l00k just k!nda d0rky. sup3r symm3tr!cal. c3nt3r3d. th0se
w3s anders0n 'Moonrise Kingdom' s0rta sh0ts. th3y don't m!x well w!th tra-la-laditional sh0ts.
Sha-a-a-a-ky cam: Great. Cool. It's all the rage. Even causes some. Don't make 'em quite so shaky.
Due to the thematic material of the entire present+past story if I wanted to mix up camera techniques I woulda stuck to only two styles of camera work: shot the present scenes on a tripod, but not in dork-O-vision, and the beach scenes in a Malick-esque handheld.
Watch your broad horizon lines for level. Them oceans/great lakes are a b!tch to level using your camera's weenie little 3" screen.
But if I were to shoot this for me I'd've proly stuck to just the gentle handheld throughout. No dork-O-vision. No tripod. No shaky cam.
But that's just me.
And for the extended edition I would've shot more of the boy at & in the water and tried to get a better match cut blend of their feet running in the water.
You really needed more fond memories filler material to pad out that entire soundtrack.
Maybe do some fade to black moments between different memories: the sand, the water, the shore, the sun and sky, etc.
Editing-wise: hard cuts for the present, long cross fades for the memories - maybe overlapping.
And don't be afraid to Foley in some audio - like the cardboard box leaves grating open and closed, splashing feet in water, lapping waves, giggling/laughing boy.
Some of that soft gentle stuff like they do in the iPhone commercials.
http://www.youtube.com/watch?v=NoVW62mwSQQ