I have to be honest, I do not know why you are having all these problems show up. I know you’ve been making custom changes, but as to what changes, I do not know. Most if not all of your issues you are experiencing, I am unable to replicate on my test site, especially with a fresh install of WordPress and the Celestial Lite, plus child theme.
- Images on your home page I can see (not broken)
- I don’t see borders in your content pages or posts with images
- as for alignment, things look in place
- social media icons became black and white…I don’t see this when I view your site and not even sure how that would happen
Regarding the child theme, on first install, it should be empty with empty folders to match that of the parent theme, plus the style.css for it should also be empty. Then any changes you do will be done from the child theme.
If you decide to not use the child theme, just make sure you do not update the theme before you check the CHANGELOG.txt file in the theme first to see what was updated. I would also recommend you keep regular backups of your site when making changes so that if something does not go well, you can revert back.
By the time I saw your site today, I’m not sure if you managed to make the above changes or not but for me, everything looks fine.
Hopefully everything for you is working now and with the replacement child theme that I provided (I had two files in there from a custom test I did for someone before and forgot to take those out, my fault).
Also, when you make changes, ensure you clear your browser cache too because this can hold old styles for a period of time and won’t show new changes.