Want to make sure that everyone knows that the security hologram WAS not from the office, but rather in the Jedi Temple. If you rewatch it, you will see it is a different exchange.
Yes, that is probably a continuity error with the Emperor line, as Obi Wan calls him the Chancellor during the rest of the film.
Burn victims have difficulty breathing on their own, but can do so without the appareatus. It's difficult and they couldn't get through every day life, but they can make it. Also, that room could have very much been like an iron lung, as was Vader's little pod on the Executor. We don't know.