While using personas is an established usability practice, it's also not really applicable to a word processor. Most people expect to be able to do a lot of things, or at least be able to load documents the get from someone else.
So it doesn't make sense to define specific tasks for each persona. All want to use all the various features from time to time (if only to view them). If Words doesn't support all of them then people will not find it attractive and will not use Words as their day to day word processor either, even if their normal use may be very simple.
That said there are also features that are only useful for very select personas. But Susan the recreational user is not so simple as she might seem at first sight.
So using Personas is a rather poor design tool for a word processor. It's much more interesting to think of use cases. 50% of all usecases would belong to Susan anyway. Now for the remaining 50% we may want to invent many personas, but I think we are just going to have two personas Susan and A.D.Vance, with the latter collecting the advanced cases, for now.
End user read would then be when it's ready for Susan.
Is a recreational user with a sharp focus on web and social media Susan would use Words to write an fancy invitation for a party, and send that around as PDF or ODT or just print it. Susan would also use Words for the occasional letter, writing her resume, contribute to a document she recieved from an interest group she has joined (maybe online, maybe the local sports club).
Below you find the use cases she should be able to do, and on this link you can find open bugs/wishes related to her
Editing and viewing different fonts and styles
Being able to change the font and style of text.
Adding and moving an image and view advanced placement
Being able to add an image and move it to a basic position. It should also be possible to load and view wrap and anchoring. However editing wrap and anchoring is not for Susan.
Mary is a first year university student studying history. She is familiar with computers as an user of typical office products, e-mail, surfing the web and playing games. She uses mainly Windows, but at home she has a laptop with Linux that her sister has set up for her. Mary is quite comfortable using Linux with a GUI. She is not so interested in computers but rather uses them for studying, communicating with friends and family, and occasionally gaming for recreation.
For an office suite her basic need is to be able to produce the kind of documents that are required for her studies. She uses mostly word processors, but also spreadsheets and presentation programs. She has to be able to easily open the most common file formats and save her documents to those formats, including PDF.
In a word processor she is used to using styles, making her own styles and importing them from an document to another. A typical document she could make would be a multiple-page document with a separate title page, an automated table of contents and page numbering (excluding the title page), as well as an automated bibliography. She might also need the possibility to define parts of the text to be written with another language than the other parts of the document, and to be able to proofread the document.
A. D. Vance
is a fictitional user where we for now collect use cases too advanced for Susan. In the future we might create personas for specific (set of) use cases.
Find the open tasks for supporting A.D.Vance on this link
Editing wrap and anchoring of images (shapes)
Setting up special wrap and anchoring so that the text flows in interesting ways