Jeffrey:
Yes, that is basically the way it's supposed to look - I have it at 1024 x 728 in the app builder so it stretches out badly on normal pages (is there a way to force it to show at the intended dimensions? I was going to iframe it to those).
And yes, some projects have missing text, so I think that isn't an error here.
Now it is strange the errors you are seeing mention failing to load and to access the "IE ALL PORTOFLIOS - SSOT" item, because that's where all the text is coming from so you clearly can access/load it.
I'm not familiar with REST endpoints - I have simply uploaded all tabular data directly to My Content, and all layers from Arc Pro.