> if use Lazy Load at ON all images diseaper but Slider is ok.
Hmm, usually the behavior is opposite: all images except ones in slider are displayed correctly. Anyway, lazy loading of images may conflict with 3rdparty javascripts that manipulate images or their parent elements in its own way (sliders, accordions, etc.) and we recommend to disable lazy loading in such cases.
> With each update, I replace 4 files to have a layout that suits me
It's better to save modified css styles to templates/mobile_basics/css/custom.css instead (this file is loaded after all other css files), then there will be no need to change internally generated files in media/mj directory.