Why do you want to return the path to the new repository instead of the repository object? I find the actual repo path not as relevant as a reference to the actual repo instance. Instead of doing

string path = Repository.Init(location); 
using (Repository repo = new Repository(path))
{
   // Code, code , code
}

why not just

using (Repository repo = Repository.Init(location))
{
   // Code, code , code
}

Same with Clone, don't you think it would be more convenient to return the instance of the repository (which is being created inside the method anyway)?