Is it possible to have too much freedom, and if so, who gets to decide what the limits should be?

It is possible to have too much freedom, yes. The government should decide what the limits are when it comes to issues that could lead to the physical harm of its people (otherwise you could just have murder in the streets without regulation). The people vote for the government so the government should be expected to hold the perspective of the majority. As for the rest of the moral decisions, there may be such a thing as 'too much freedom' (also known as 'chaos') but it should be solved by respective social and religious groups rather than the government. The dividing line between which issue belongs with whom is tricky.