Rollerball or any of you guys recommend a tutorial for aircraft tweaking? I'd like to give it a shot...

Nah... no such thing. Just get hold of the aircraft container SDK that'll explain everything about the cfg file. Then just use basic aerodynamic theory to make changes - you know, what happens when you change power, lift, drag and weight factors.
The air file is something different. M$ have NEVER to my knowledge published any details on the air file - everything we know is down to what people have discovered by tweaking values and telling others about it if they find something significant.
All you can do is use Aired.exe, common sense and a willingness to experiment. Yeah - and always back up the original and the LAST GOOD version of everything you create. I've lost count of the number of times I've made a good file, changed it, got rubbish and then forgotten exactly what changes I made from the last version ::)
Can't give you any more advice...

Except one more thing. X-Plane this is NOT. Do NOT make the mistake that people like POSKY did in the past. The M$ files are not based on exact science. You can't expect to put real world values into M$ sim files and get real world results. The files are not that accurate. All you can do is play with values until you get what you believe approaches similar-to-real performance.
Final advice - just go for it 8)