1) Is it a hassle carrying it around and transporting it???
2) Can you easily sit with it on your lap???
3) Is it too big for a laptop??
4) Can you use it easily in coach, which i will most likely be in??
5) Does it get too hot to use on your lap when playing games or watching a movie???
I fly regularly on business and pleasure, and have toted my MBP around where I go. I use a Marware neoprene sleeve which does an excellent job of protecting the finish against scratches and minor dings. I also leave it in the sleeve whenever I go through security at the airports and have never had to take it out, a big pro IMHO.
1) Not at all. Just get a sleeve, and since you are a student, make sure to get a backpack with a laptop compartment that will fit a 15" widescreen, many do. I use an OGIO Metro. Fits the Marware sleeve and it doesn't even look like I'm carrying a laptop.
2) I love using it on my lap. I actually find typing easier this way. The screen angle when fully open is a little less than I personally find optimal. I think an extra 5-10 degrees would have been ideal.
3) This is very subjective, but I use mine for business and pleasure. At work, I deal with spreadsheets, word docs, software development, project management, using Parallels and VMWare to test technologies in different OS environments. The MBP 15" is a very good trade off between portability, performance and screen real estate for these uses. At home I use it to browse the net, play with Photoshop, Illustrator, and iMovie. Whenever I need more screen real estate, I just connect an external monitor. IMHO, this is NOT too big for a laptop, but is the perfect size for my needs.
4) I've found this varies depending on airline and airplane. On many of my short hops, I fly in Canadair planes configured for regional flights. These usually cater to business travelers, but are all coach seats. I put the MBP on the tray, and it works great (the seats on these planes don't recline). On mid-range jets like MD-11 or 737s, it's very difficult to use. If you use the tray, you need to pull the laptop very close to you, and also need to be on guard to make sure your lid doesn't get munched by the person reclining in front of you. If you fly JetBlue, the MBP fits well, but you should position it midway between you and the seat in front of you. All in all, this is a long post basically saying, it's possible, not ideal, just be careful and you'll manage.
5) Definitely gets TOO hot. Under load you cannot put it on bare skin. Even with jeans on it is beyond my threshold of pain. Invest in a laptop cooler. Not only will you be able to use it comfortably on your lap when maxing out your MBP, but you may also be prolonging the life of your machine.
The biggest question I have for you is do you really NEED a MBP? As a college student, do your classes and or hobbies really warrant the extra expense to have the MBP? Given the latest MB refresh, you could get a very capable machine that is more durable for significantly less money. My main motivators for the MBP were the 3GB RAM, 2.33 C2D, and 15" widescreen for working with code, multiple OSes and graphics work. If you'll be using it mostly for writing papers, playing music, storing pictures and surfing the net, the "cool" factor of the aluminum MBP might be too much maintenance (not to mention expense). I constantly obsess about not scratching the case, or tweaking the lid (I could be more obsessive than most, but read around, these are common realities of living with the MBP). Regardless, my overall answer to you question is a resounding, YES, the 15" MBP is definitely portable.
