unfortunately I am not abel to follow the steps you described and I as well can not imagine what you want to achieve.
If the participants just shall stop the survey and shall be able to complete the survey later, you can add a "cancel button". The survey then will be closed but you are not able to ask them further questions.
You can add an external survey start to forward participants to a second survey. The answers from survey 1 and survey 2 then can be matched if you transfer the LFDN from survey 1 to survey 2 using URL parameter.
Though, you can not directly link to a special survey page as tere are no special links for each page. You can see this when previewing different survey pages. The URL in the browser does not change. There is not value "page_id" in the URL. You therefore can not directly jump to a specific page.
You can not integrate EFS Survey questions in a pop-up window. If you create questions yourself with HTML then the answers can not be stored in your EFS survey.