Hints and Tips: Re: look and feel deselect
It's not so much a case of "deselecting", more like selecing what you had before. You can't have no theme at all - you always need to have some sort of theme chosen.
Currently your site has the Bootstrap theme selected.
Previously i think you had the Blue menu with green wavey header theme - so you can go back to Look & Feel and select this one if you wish.
I strongly recommend that all sites use either the Modern or Bootstrap theme. These two themes are the only ones that really work well on mobile devices. The other themes are older and don't scale well on small screens.
The Modern and Bootstrap themes both have loads of configuration options to allow you to tweak the colours, styles, banners, menu position, etc.
If you use either Modern or Bootstrap then any visitors using mobiles or tablets will have a better experience. And your site will also have a better Google ranking as search engines prefer sites that work well on mobile!