[MacG5]

How Do you want to make the report, based on what? Numbers of task to complete? Remaining time to spend on these tasks?
I'm just wondering why you spent so much with reporting "...status reports can sometimes take me *HOURS* ..." instead of DOING the work. OK, you mentioned that you have to do this reporting - hopefully for someone else. But the problem here, generally for projects, that the more precise you want to calculate the remaining time the more divergence you will have with the actual result.
Make a weekly review, and a good estimate. YES, make a guess, it will be as good as the best scientific calculation plus the resulting deviation. No one will see a difference, but you, having more time remaining.
Still in doubt? Here's an example: Project with 4 task, you add another one, just phone call task; a report as you mentioned above will show an increase of 20%. Doing the task will show a progress in the project of 20% - what? it will take you just 2 minutes to make the call. That would mean the whole project is equally built out of equal task. To avoid that, you must give each task a specific estimated duration, that may (no, certainly) vary with time. So you have to adjust these parameters EACH time you review, so it is still the same as you do the estimation.
I would agree that it would be fine in OF if the "duration-column" would be calculate the sum, just as omnioutliner.
Then the rest of your requirement would be just to define proper perspectives and make a weekly review for the report.