D: I'd rather figure out a scalable way to add a help icon button to all dialogs and direct each dialog to its corresponding wiki page. This would have the additional benefit of needing no text changes and can therefore be a 'rolling change' in 7.0.
T: The help text for -cm is "Sets the 'Comments' for the currently selected task". I recommend changing that to "Adds to Comments for the currently selected task". ( Is there a way to actually Set/Replace the comment rather than Appending to it?)
D: Agree totally. An option to replace the comments would have to be a feature request in 7.1.