This is the current look - it will be being repaired at some point from the many earthquakes we have had over the last two years and it is currently a very dark room. I would like to warm it up somehow. Suggestions? I did consider, white panelling 1/3 way up the wall and a collection of mirrors to reflect the light in.

What a fun space! Love the pillows...I agree with above, lower all the frames, but not so low little ones can reach. The art should fall at eye level about 5'4" for walls and for behind the sofa not more than 12" above it. Then keep the width about 5" inside the sofa length on each side. Your frames are small so you need the close together for impact. I would start with some pretty curtains for the door and large window and then a simple Roman shade for the small window- since your girls play there you don't want anything they will grab hold of. http://www.houzz.com/ideabooks/query/how-to-hang-a-photo-gallery

None of the above - I love prairie, desert or mountain scapes. The water photos are too "cold" looking (I've experienced both - I still feel chilled when I think of it), the mossy forest is a bit creepy (beautiful but creepy) and I'm not fond of having humans on my wall - even if it is as minimal as a child's hand holding a dandelion (the sky in that photo is to "cold" looking - like a cold fall day). That's just me. They are all great photos. Just not my style.

Wow - what a view! Yes definitely take the curtains to the ceiling it will add grandeur and frame the view even more beautifully. You can get a custom bent track made that will take the curtains around the corner so the window is not obscured when the curtain are open. Contact your local interior designer - they'll know what to do