For the featured images, the option in the Customize -> Blog -> Featured Image -> Enable Featured Images was disabled. This we will fix in the next theme version. For the excerpt issue I recommend sometimes switch to the text editor, as it will clean all unwanted spaces/codes which can break the code – http://prntscr.com/mfgc6l
The excerpt for the portfolio templates is generated from the content, not from the defined excerpt. If you need to define your own excerpt, we will need to modify a code. Best would be use a child theme, then you will not lose the customization. What we need to modify is this file – custom-templates\template-parts\portfolio\content-catalog.php line #27:
This is odd because I have another website https://cambeas.com/available-puppies/ that I am doing exactly the same layout and it works perfectly fine. So why would there be a need to develop a modified code?