The secret life of text

I've been looking at the intimate relations of writers and their text to investigate how the written medium might carry the message.

On screen writing is easier on the eye, apparently, when it uses a sans serif font(one without the extra edging on each letter).
On paper, serif with its extra flourishes are, apparently, easier on the eye.
The default for mobile phone texts appears to be sans serif.

Apparently for higher academic grades, go with Georgia, at least according to a curious but lively little blog on The Secret Lives of Fonts posted by Phil Renaud on March 12th, 2006.
... or at least that's what was seen as preferable, back then, or more authoritative, or matches what newspapers (such as The New Yorker).

But my searching didn't answer my own question which is about showing multiple voices in a thesis and so am still curious of ways to do this.

Bruno Latour's, Aramis or the love of technoology divides the sections of different voice with inserted lines and changing fonts: using Times New Roman font for the main text to one sans serif for documents, and different again for interviews (where his own prompts to the conversation are italicised), different again for a senate hearing of multiple people that is all italicised but reads like a play, and also seems to change font between what is current time investigation to that which is written in the third person posturing a more theoretical voice, and then an italicised font for Aramis' voice.
It does get a little hard to follow.

John Law, in Aircraft stories, puts in the advertising voice as an inserted exhibit with sans serif. He also puts in pertinent conceptual discussions as a boxed text.
To my mind, it could have done with more voice.

I will continue this search for a text life
:)
Happy to hear your views, or any reference to other texts that speak in multiple voice.
Its for a thesis, so I may have to draw the line on use of coloured font.