Testing is key to making usable forms - the opinions of the organization and the designer pale in comparison to the experience of actual users when they approach the form.

At the very least, do a "hey you" test - grab someone who is not familiar with the project and ask them to go through the form while you observe and take notes. It's quick and dirty, but better than nothing.

Better yet, do lab testing.

A "paper test" can be useful, but it is not as good as having users interact with a functional prototype.