Yes it is possible to get stronger doing bodyweight moves, but after a while you will lose progress without increasing weight. Also, if you want to get stronger, you will gain muscle mass, no matter what. Strength equals muscle.
You should understand most elite MMA athletes don't look like what you see in the cage at all times. That is when they are at their peak conditioning. They will train for size and strength in between fights, then when training for a fight, they will alter for more endurance and conditioning versus pure strength.
And to get ripped, you need to have well developed muscles, including abs, and low body fat. There is no workout you can do that will just give it to you.
At 16, you have a good base to build with. I would focus more on overall conditioning versus strength right now, until you get more weights or can make it to a gym. When you are ready for a developed routine, look up some basic 5x5's. They work, if they didn't they wouldn't still get used after many years. And please dont focus on getting huge biceps. Having huge biceps may look good, but they will give you little advantage in the cage. It might also help to read a book on muslce physiology, so you know what muscles do what, and how to train and prevent injury by overworking one area. I do like how you noticed low leg work in one of those plans, legs are very important for a good strong body.
Your diet also plays a big role. If you don't eat right, you can train 1x a week, or 7x a week and make it nowhere.
Mt Snow, VT - May 5, 2012 - Completed!
...i remain, he who remains to be...