Remove the Start Course Button in Rise?

Yes, my suggestions are intended only for an exported course (web only or LMS) - but as Stuart points out, you can remove the "Begin" and "Details" button directly through Settings>Labels (so I was over thinking it). 

Unfortunately, there does not appear to be any way in the Settings>Labels to remove the inverted caret/downward chevron (so you can hide the  "Details" button but you are left with the inverted caret/downward chevron only). So currently, the only way to hide the icon is by hiding it using the CSS change. Articulate really needs to address this through the Settings>Labels (e.g, make the icon optional, let the user select an icon to go with label text, etc.).

Also, to clarify my "C" suggestion above - my ONLY suggested addition/change was:

visibility:hidden;  

I was simply showing the steps to locate the location in the file to place the visibility:hidden; property  (for those who need/want detailed instructions).

Finally, here is how you can hide the progress bar:

E. To Remove the Progress Bar

1. Open main.bundle.css in a text editor;
2. Search for “.progress-bar” ;
   
   RESULT:
   

   .progress-bar{font-weight:700;text-transform:uppercase;letter-spacing:.12rem;font-size:1.1rem;color:#fff}

3. Add ONLY the "visibility:hidden;" property; and
   
   RESULT:
   

   .progress-bar{visibility:hidden;font-weight:700;text-transform:uppercase;letter-spacing:.12rem;font-size:1.1rem;color:#fff}

4. Save the file.