As for the second, There is no shell=True for me in the demo but it is present in the code you sent. So maybe it is just a bug in the presentation somewhere.
Scrolling to the right should work, but you'll need to do so on each code editor section. We should combine scrolling of these two windows to be in sync.
We'll also take a look at what's causing this. It might be a browser issue.
They scroll in sync for me, but long lines seem truncated in iOS 16.2 Safari. No visible code on that second linked page includes the string in question.
As for the second, There is no shell=True for me in the demo but it is present in the code you sent. So maybe it is just a bug in the presentation somewhere.