No one will be able to go to the secure site directly by typing the url into their browser. They will have to link from the non secure site.
Also, the things they will be able to do after registering will require ajax as well. That provides the quick functionality. There will be a database involved. If it slows down, I'll upgrade the hardware.
I'm still learning to code. There will always be a learning curve to coding. It won't always be as steep as it is now, but it will always be there to some degree. I don't have all the answers. I have to make some decisions about how to do things, and see how it goes. No one method has all the advantages and no disadvantages.
Thanks for your feedback. Thanks for helping.