As long as Putin continues his aggressive agenda to somehow reconstitute the old Soviet Union then we have not gone too far. I submit that we have not gone far enough, since he continues to assist rebels in the Ukraine, sending agents in to agitate and destabilize the country so he can annex some part of it. We need to tighten the noose more firmly and let him know that there are consequences that will affect him as well as the less fortunate people in his country.
It's difficult to say exactly how much US sanctions against Russia have affected the Russian economy. While they've certainly had some effect, it's no secret that many of the political and economic leaders of Russia have openly mocked the sanctions. In a sense, those in charge are so wealthy and so far removed from the lower edges of the economy that it may be very difficult if not impossible to hurt them financially. But still, we must try, for what they are doing in terms of foreign policy is simply unacceptable.
Sanctions don't always work but the other position is too horrible to consider. All out war would be devastating to many of us, especially to Europeans who are still struggling through the Great Recession. Sanctions may be the only tool in the arsenal to convince Putin to back down and allow the Ukranians to fumble through their democratic process. When things don't go your way, antagonistic hostility will not achieve the day. Some people need to be told to "stop;" Otherwise, they will keep on running forward.
The United States hasn't gone too far in the current sanctions against Russia because sanctions are the only way to change a political course. Most of the time countries are intervene in a situation based on their financial interests. Russia will changes its political point of view regarding Ukraine only if the Russian government feels that economically there is a downgrade. Once this downgrade is tangible, the Russian government will changes its point of view in order to avoid demonstrations and having its own people against the government.
I don't think that the United States has gone far enough with the sanctions. At the end of the day, Russia is fighting in another country, and trying to land grab. Ukraine is also a member of NATO, and the NATO pact is that each country will jump to the aid of any other being attacked. We would be moaning if it was us that were being attacked, and our "allies" were to do nothing.