Hi Vince, sorry to hear the trouble!
As you have discovered, right clicking to download the ebook doesn’t actually provide access to it. You will have to go through the checkout process.
However, I discovered something on my end too on the backend: an incorrect setting that charged shipping for the ebook. My bad! That setting has now been corrected and you should be able to “buy” the ebook through the Store for free.
So, go to http://www.lenspiration.com/freeebook, add the ebook to your cart, and proceed through the checkout process. Once completed, an email with the download link will be sent to your email.
And yes! You may download it to as many computers/devices as you’d like via the link in the email!