Without a doubt its production problems that caused these. I haven't been to film school, but i know what you mean by the 180 thing, and i think it makes much of the Venice portion hard to follow in Othello.
I think it works against Othello in those scenes, rather than for it. Welles thought the same, i think - he said he thought it was mainly poor in Venice, the effect of the money/production problems, in the BBC (i think...) interviewlets shown on the Criterion Othello.
Welles would never choose anything that didn't work in those films where he had a studio at his disposal - everything in Ambersons, visually, is perfect. In those two RKO pictures he did very few cuts - most scenes played out in one shot, and finished with a close up, like Shakespeare finishing a scene with a rhyming couplet. It was only later, IMO after certain experiences with editing, especially the editing of Ambersons and the experience being an (the first) independent filmmaker on Othello, that Welles came to have a taste for what might be called 'shards of glass' editing (there's probably a film school term for what i'm describing), seen in full flight in F for Fake and Other Side of the Wind.
Aside from the studio pictures, i think most of his independently produced films ran much smoother than Othello, b.c they were shot much more continuously (i'm thinking Trial and Falstaff in particular, by far my favourites of the independents).
You may remember me from such sites as imdb, amazon and criterionforum as Ben Cheshire.