It is
NOT the carbs that make you fat. Don't fall into the latest low-carb craze and get confused, please. Carbs are ENERGY. If you want to run, workout, whatever, you NEED carbs. Just keep them in check, don't overload. They CAN make you fat if you don't work them off. Because what is fat? Stored energy. If you don't burn off that energy made by carbs, then yeah it'll turn to fat.
The secret (not a secret, more like common sense but calling it a secret sounds better) is to burn off more calories than you consume. That's it.
You're right about saying that doing crunches won't make you lose fat just on your torso. Fat goes on
and comes off in proportion. You can't work your stomach fat, then your left arm flab, etc. It just don't work that way. It all comes off together. Also, crunches don't make you lose fat at all. I don't think that's what you were trying to say, just using it as an example, but I'll point that out just in case!
There is no reason to not gain muscle if you are fat. Sure, it's good to shed off that extra flab before you really get going on muscle, but not required. The stronger you are, the more tone you'll have no matter how much body fat you have. Everyone after gaining muscle mass has to "cut" anyway. No reason to cut, gain, then cut again. If you're #1 thing is to get stronger and gain more muscle mass, just do that. Then lose the fat. If you just want to lose fat, well then go ahead and focus on that. But don't ignore the weights completely. You'll want some tone so you don't look like a stick figure.
To lose fat, you want to do cardio exercise. Cardio exercise consists of: running, jogging, walking, swimming, rowing, biking (great), stuff like that. Best way, even better than the cardio, is called High Intensity Interval Training (HIIT). Google that for more information. It's difficult, but it pays off damn nicely.
For muscle building, hit the weights (duh)! And remember to get your protein. You need at least 1 gram of protein per pound of body weight. For example, if you weight 170 pounds, you need to take in at least 170 grams of protein a day. Stay away from too much cardio when trying to gain muscle. I don't do any cardio at all when I'm putting on muscle, but it's okay to go for a 30 minute jog once a week or so.
...some of that was a reply to the quote and then I just got carried away. Sorry.