Sakura-Tribe Elder is a good card, plain and simple. I have seen it in almost all decks that have good enough of a Green base in them. The one distinction we have to make when we look at the Elder is that its ability is never game changing. Playing the Elder will not change the how game has has developed much; the ability is great, but only as a support ability - it makes what would be a good deck a better deck. Whereas cards like Eternal Witness and Fact or Fiction are game-changing. Playing the Eternal Witness at the right time can effectively win you games, and the same with Fact or Fiction.
Solemn Simulacrum is another great card, which would have been better off cost 5. Another design flaw. However, given all that is given, Solemn Simulacrum is not a game changing card. It's a great card, but it can't be abused easily, and although I have seen it in many decks, I just don't think it has a big of an effect to warrant questioning its power level. Nevertheless, I would have made it cost 5, certainly not 4.
For "efficient counterspells," I am not sure what you mean. Counterspell, perhaps? Certainly, Counterspell has no place in current Standard environment, not even as a rare. And this is coming from a devout Blue player. How about Hinder? Hinder...is a very good card. Annoying to play against because it has 2 different strategic purposes, each differening than the other and requires a good deal of thought to play efficeiently. It is perhaps the most complicated counter Blue has, stragegy wise. Everyone can play 4 in their Blue decks, but not many can play them wisely. Same applies to all counters, but more so to Hinder. I have no problem with it. How about Dismiss and Rewind? Dismiss is a great card and I would really perfer it over Rewind, though Rewind is a good card too. Both aren't too big of a deal to complian about, and being counters, they both require brains to play.
Dual lands? They're all broken. I wouldn't have printed them, I wouldn't have even suggested them.