You need to split the questions up and you shouldn't have them on one single page. I would review the hierarchy in which the questions need to be answered and see if some of the questions can be placed in a trigger so if someone says YES to a question it will expand the other set.
Look into a multipage form to prevent annoyance by the person filling it out. If this is to be for a website and you're going to go the route with a multipage form I would also implement a completion bar so it will communicate back to the person filling it out they're almost finished.
Another perspective to look at the whole process is you need to have disclosed what is required and what is optional. I cant imagine what questionnaire would require 700+ questions. If they all aren't required I would minify the questions and allow a second option of the download if they really want to fill out 700+.
After image edit:
Everything looks like it is crammed together. 5 & 9 look like they could be the same question in Property Location / Contact. You need less columns and better implementation with more space. Too many things going so look into adjusting all the checkboxes. If someone was to start filling it out, based on the space you have there, there is no way to tell if the input field they are filling out is directed to the text above or below the field.