I don't think Iran has done anything to warrant the sanctions in the first place. The IAEA keeps saying that there is no evidence of a weapons program. Even the US National Intelligence estimates that Iran hasn't had a weapons program for a decade. Iran is guaranteed a right to civilian nuclear power under the terms of an international treaty, and there really is no reason to suspect they want weapons. There is certainly no justification to act on "suspicions" like that either.
The problem resides with a certain group of American politicians who desire another war in the Middle East, and a complicit media who broadcast falsities such as the "wipe Israel off the map" statement. Admadinejad didn't even say that, but I'm guessing a majority of Americans and Brits still believe he did because the correction wasn't given nearly as much coverage.
So, to answer the question... no, there is nothing wrong with lifting sanctions, and in my opinion, America shouldn't even be asking for anything in return. As for the French, their pro-war-anti-negotiation stance has become all too clear in recent years (Syria, Libya, central Africa, etc)