Those are some beautiful pics! I think it's a lovely layout as is, but if you wanted to change something, maybe try this (and I am
NO graphic expert, that's for sure - this is just my opinion as a scrapper):
I can't really explain balance either, other than it makes everything look "equal" on the page - there is a focal point on the page and everything else on the page compliments it, rather than takes away from it. One part of the layout doesn't look overly "heavy".
Maybe the square photos are competing for attention amongst themselves as they are all similar in size, as well as competing against the larger, b/w picture. Maybe try adjusting the sizes of the square pics so that they are all equally smaller, or maybe gradually smaller, and then aligning them against the lower left side so that the larger, b/w picture becomes the focal point of the layout, towards the left side.
Or ... just totally ignore me because really, I'm definitely "askew" challenged and need to have alignment in my layouts; simply tilting an element drives me insane. I am probably the last one who should be giving out any balance advice.
