by "the book" do you mean the wiki instructions at https://github.com/fritzing/fritzing-app/wiki/1.-Building-Fritzing ?
A couple of things have changed in the last few weeks, due to the introduction of libgit2.
But if you can run it properly under Qt Creator, it seems you're good with that.
Qt Creator is configuring the run environment in the background, so if you just click Fritzing.exe, you are missing that. You could try to recreate the same situation manually. The first step would be to put the path to the Qt libraries into your system PATH variable. Then you need to put any other libraries into that folder, and you also need to provide the -f and -p arguments that point to the fritzing-parts.
But that's not the recommended way. What you're trying to to do is actually the same as what we do when we publish a new Fritzing release. There is a full instruction on that, including a release script that takes care of all the above mentioned steps: https://github.com/fritzing/fritzing-app/wiki/4.-Publishing-a-Release