[whpalmer4]

If you have multiple projects for a client, you might consider instead making a folder for a client, and individual projects for the projects. That will give you more control over reviewing, putting some projects on hold, etc.

It sounds like your projects are not sequential, as you are asking for the actions to be sorted by due date. OmniFocus assumes the order in which you arrange actions in project mode is significant unless you tell it otherwise (by marking the project or action group as parallel). Otherwise, if your project had two actions, "Buy paintbrushes" (no due date) and "Paint house" (due date) in that order, and you had it sort by due date, it would show "Paint house" as the first thing to be done, even though you couldn't act on it in real life before buying the paint brushes!

OmniFocus operates on a project as the smallest unit in project mode, so display sorting sorts projects, not individual actions. In context mode, actions are the smallest unit, so the display sorting in context mode sorts by action. In either case, these sorts are merely rearrangements of the display, and if you open another OmniFocus window, you can see the same data simultaneously arranged in a different fashion by changing the view bar settings. In project mode, you can also do a destructive sort which permanently rearranges items, just as if you dragged them around with the mouse. This type of sort is done by selecting a bunch of actions, and then doing Edit->Sort-><sort type> or by control or right-clicking in the outline and selecting Edit->Sort-><sort type> from the popup menu.

So, if you simply want to look at a list of all of your upcoming due dates, sorted chronologically, you would go to Context mode, and set the view bar to show "Due or Flagged" actions, and use the grouping and sorting selectors to fine-tune the arrangement. Grouping by due will get the actions chunked into groups that are smallest around the present, growing larger as you go farther into the past or future. Sorting you might do either by due or by project depending on whether it is more important to see the actions for a given project together or have the most accurate timeline.