I'm sorry, I still do not understand your question, and the pictures make me even more confused, because they don't seem to have anything to do with your question about resizing the page. Now you are showing a menu, which you never mentioned! It seems you are asking many different questions - can you ask about just one issue at a time?
You do not have to reload the page in order to resize elements when the browser window size changes. Nor do need to use any jQuery either. Google for "responsive design" and "CSS media query".
I see you are doing something with hover. Hover does not work well on touch-screen devices, as they don't really have a "hover" functionality, and they all fake it differently. Any, anyway, the user's finger blocks the hover, and so it really is not very useful. I would never use a cascading menu on a touchscreen interface! If this is mainly for touch-screen devices, I think you should re-think your design.