Hash

Please follow the proper way while making child theme. The theme does not have any compatibility issue with the child theme.

And we are not sure about the problem in your child theme unless we see it so we can not give you any solid suggestion currently but can suggest you to try making child theme again following the rule.

Hi,

The portfolio is working properly in the mobile device. We have tested and verified it.
Now the zoom button and link button displays initially without having to click on it.

The theme shows the full post in the blog page. You need to limit it yourself by using the default feature of the WordPress. Here is the link for reference http://www.wpbeginner.com/beginners-guide/how-to-properly-use-the-more-tag-in-wordpress/

Hi,

The theme is designed with certain layout and certain section so theme does not allows to add any extra section or any extra layout with out having to customize the code.

But if you are using some page builder then you can use it to create your own layout by choosing a static page for the home page but again you can not combine the page builder with the theme default home page layout.

Thanks

If you want to only show 4 service page then in the field of the service, just make sure that you only choose 4 service page. Leave other extra field blank.

Here is the code in the file inc/breadcrumb.php

https://themes.trac.wordpress.org/browser/hashone/1.2.0/inc/breadcrumb.php

Line number 13

HI,

Try adding the below CSS.
Also it is important that you upload proper image size. You may try resizing or cropping the image until the size looks good.

.hs-service-left-bg{
background-size: auto !important;
}

Yes, it is possible. Go to Settings -> General in the dashboard menu. In the field “Date Format”, you can choose from the available date format or add your own format.

The code you mentioned should work. Also you need to add some more code.
Here is the complete code. The code works for single post, page and archive page only but will not work on home page if set as Home template

#primary {
width:  auto;
float: none;
}
#secondary{
display: none
}

The title and sub title does not does not support HTML tag. All the HTML tags added will show as it is. These section are only intended to have short texts.