If all else fails then read the documentation (I was going to say something ruder :))
If your layout has images, you probably need to use imagesLoaded.
Overlaping items are caused by items that change size after a layout. This is caused by unloaded media: images, web fonts, embedded buttons. To fix it, you need to initialize or layout after all the items have their proper size.
Your images are way too big a file size anyway which exacerbates the issue. Those little post images are weighing in at 150k each and you have over 20 of them!! They could easily be optimised down to about 15k each and save half an hour download time
Your big background image is 800k and should be 200k max. You can't see most of it anyway so probably could be much lower than 200k.