A compelling value proposition is a sales pitch. Use it wherever you are trying to draw attention to what you are selling.

An Informational Presentation provides information to your audience. It is a visual aid used to accompany a talk. It should not dominate the talk.

A Sales Presentation is used to sell your product or service. It is only a visual aid accompanying a talk. It must have a call to action.

Proofreading a document usually involves some simple "tricks", including quickly reading through the document to get a "feel" for it; reading the document aloud to see if it "sounds" right; and reading the important parts backwards, such as headlines, quotes, and important information like addresses. Preferably, have a second person present to help detect the errors.