Hi Alton,
1. To force the opaque text box that appears over the slider image on front please go to Appearance -> Customize/Theme Options -> Design Options Tab -> Custom CSS paste the following CSS code and Click on save button:
.featured-text .featured-title {
background: rgba(5, 169, 197, 1);
}
.featured-text .featured-content {
background: rgba(85, 85, 85, 1);
}
2. Yes we have hide the featured slider title/content in smaller devices because of overlapping issue in the image.
3. Please clarify what you are trying to do for description box?
4. Yes you can set the slider number as your wish for that please go to Appearance -> Customize/Theme Options > Featured Post/ Page Slider Slider Options there you can set the number of slider you want to have in you site.
Thank you!