Visual Composer sections inconsistent and unresponsive.

I have 3 visual composer rows on the home page of my website (gospellifefc.com), and they behave differently on every single device I’ve tested them on (Mac:Firefox and Chrome, and Safari on both iPod Touch 5G and iPad Air)

I have several rows with columned out sections.
The 3 rows are split like so:
1/3 + 1/3 + 1/3
1/4 + 1/2 + 1/4
1/12 + 1/3 + 1/6 + 1/3 + 1/12

On the first row, in the middle, I have a fullwidth video with a poster specified. It works fine on PC, but it’s a lot larger than the containing column.
On iPad, it is larger than its column and doesn’t play the video or show the poster.
On iPod, it is larger than the screen and simply shows an ”unplayable video” button.

The second row has a simple countdown timer, which fits on the 1/2 segment on computer, but not on the iPad or iPod.

And the last row has a fullwidth parallax image section on the 1/6 segment in the middle (I want to get the parallax effect on smaller sections of the website than the full width. I also want to be able to use it in posts and other parts of pages.)

Why is nothing behaving in a responsive manner? What is the deal with fullwidth sections? Is there no way to have a parallax effect outside of the fullwidth sections using the standard Theme tools?

Thanks in advance for your help.