Hi Donald. Yes, I think as a 25 year old fit male you can run a sub-3 marathon if properly trained. Run consistently and get your weekly volume up as much as you can (ideally at least 60 miles per week, but 75-80 would be even better). Get at least two interval and/or tempo workouts in per week. Get a weekly long run in. Your work schedule is a bit crazy -- doesn't seem like you have any time for morning runs at all unless you are up at 3AM, but then you compromise your sleep and recovery.
If you review the "Training Review Requests" threads you will find a lot good of advice there. A good place to start is here: http://fastrunningblog.com/forum/index.php/topic,1744.0.html
. Jon links to other good threads about training that have a lot of details about all things marathon training and getting faster.
Back in the day, this forum was a buzzin', but unfortunately now it's mostly dead. You probably won't get much more feedback here. It's nothing personal -- people just don't use it anymore.
For the few people who still blog consistently on here, you may want to follow their daily training and reach out via comments if you have questions or are looking for feedback on your own training.