1.5 – Can I come back and address this info later?

Yes.  Absolutely!  There’s no issue with returning back to the point where you left off.  However, there is one caveat.  You’ll want to make sure that you save the section you’re working in.  

For example, if you take half your body measurements and load them and then just close the browser window, that’s not going to be saved.  What will need to occur for saving is the completion of the screen you’re currently working on.