The only thing I question was the paperclip ring. Really, Day?
About the 10 years, why do people complain so much about it? I think 10 years is just right in order for the Republic to accomplish many things and make peace with the Colonies, for a relationship between Anden and June to flourish, take place and reach its end, etc etc. But most of all, I believe the real and main significance of the 10 years later epilogue was that June is finally her brother's age when Metias died. I will not further elaborate, but just think of Metias dying at 27 and now June who will be older in the years to come, older than what Metias will ever be.
I sucks at explanations, so just let your thoughts wander and ponder over the matter. Then, you'll get why "10 years" was the right choice.