Loosing flab and putting on muscle mass at the same time isn’t the easiest thing in the world to do. Since you said you are a genetic freak, I’d focus strickly on losing fat and gaining strength until you reach a point where you want bulk up.
An excellent all around strength builder with limitted equipment would be the one-hand dumbell snatch for reps. This will hit your entire posterior chain, your core, shoulders, and forearms pretty well for strength endurance. It will also increase your explosiveness as well due to the ballistic nature of the lift. Not only that but you’ll be sucking wind like a mad man, so it will definately increase what you have in the gas tank. To do them, position you body like you are about to deadlift and hold the dumbell in a hang between you legs. Thrust your hips forward straightening your legs. This will start the dumbell on its ascent. Next, just use your shoulder to keep the dumbell’s momentum all the way up so you end up holding the dumbell overhead with a straight arm. bring it down and repeat. It should all be in one fluid motion.
A dumbell clean and press is another good exercise for full body strength and explosiveness. 3 sets of 12 would be a good place to start.
For more conventional strength training, you can also throw a bench press in there as well. It will increase your pressing strength a bit as well as add some superficial appeal. 
A pull-up bar for your place would be a good investment as well. Nothing can build and strengthen the back and biceps like pull-ups.
The routine would be something like say M,Tu,Th,Fri
Mon,Th -
Dumbell Snatch x 3 sets of ladders: Do 1 snatch with each hand, take a breath, do 2 snatches with each hand take two deep breaths, etc… Do this until you know you won’t be able to complete the next set. Do not fail!! That is important. When you won’t be able to complete the next set, drop back down to 1 and start over. Do 3 ladders like this, then rest a couple minutes, repeat, rest, repeat.
Pull-ups: I’m not sure how much pulling strength you have. Whatever your max is multiply that number by 4 and do those amount of pulls in the least amount of time possible. Say your max is 7. Do 30 pull-ups like 10 sets of 3 reps in 10 minutes. Keep adding when you can to eventually get to 10 sets of 10. You’ll be a pulling machine by the end of a cycle like this. My max shot from 8 to 20+ after a couple months of doing this last summer.
Tu, Fri -
DB Clean and Press 3 x 12: Just make sure to leave a rep or two left in you. Again, you don’t want to fail.
DB Bench Press 3 sets of ladders: 1-2-3, 1-2-3, 1-2-3 rest, repeat, etc. You want to rest for the same minutes as the amount of reps you just did. ie 1 rep rest 1 min. Rest 3 minutes between sets of ladders. Use your 5RM max for weight.
Pistols (one leg squats) 3x3: For this one hold your hands out in front of you like a zombie, lift one leg in the air like a front kick, squat down butt to heel and back up. Do 3 sets of 3 for each leg. You may want to start holding onto to something for aid and balance. When your strength increases start holding a dumbell or weight plate in your hands for added resistance.
The dumbell snatches should really hack the fat away, and the other lifts will give you a good foundation to build from. After about 4 months of this, you could start adding some squats, regular deadlifts, and some other more conventional work to add maximal strength and size. Having a good foundation to build from is extremely important though.
For complete bodyweight workout ideas go to:
http://www.trainforstrength.com/index.shtml
http://www.webfects.com/hea/routine.htm
Some other good strength forums are:
http://www.dragondoor.com/cgi-bin/tpost.pl
http://pub17.ezboard.com/fanimalabilityanimalability
http://pub26.ezboard.com/boldschoolstrengthtraining70757
On of my favorite bodyweight workouts is this. You may want to give this a try as well as this tears the fat from your body:
A playground is the best bet for this as you need sprinting room and pars to do pull-ups from. Set up 6 cones. One at 10 yards, 20, 30, 40, 50, 60.
Do 20 hindu (shootfighter) squats and then 10 push-ups. Without any rest do 20 more squats and 12 push-ups. Do this until you get to 20 squats and 20 push-ups.
Immediately sprint out to the first cone and back and do 5 pull-ups. rest 20 seconds and sprint to the next cone and back and do 5 more pull-ups. Do this until you’ve sprinted out to the last cone and back and do 5 pulls after each sprint.
Reverse what you initially did. ie 20 squats/20 push-ups, 20 squats/18 push-ups… down to 20 squats/10 push-ups. Again, no rest at all!
Reverse the sprints as well. ie sprint to the last cone and back/5 pulls and rest 20 seconds, etc etc.
Make sure you have water and a puke bucket handy. I nailed two of my friends with this one. hehehe.
Hope this helps. Let me know if you have any more questions. Train hard!
