EVH is spot on. Some companies WILL screw you over, there's no way to avoid it. It's also borderline impossible to break into the film/photography world in "action sports" on a good paying level. BUT, there are great paying gigs out there...
I mostly film motocross (I leave my cameras at home when I go skiing) but to answer your question - it's an awesome life. I get paid to travel and hang out with the best athletes in the world. It's an extremely time consuming, stressful, frantic, and unglamorous life but it's awesome haha
The pay level isn't the kind of info most people are willing to give out. When I first started that was the hardest thing for me to figure out. On multiple occasions I completely undersold myself and even oversold myself right out of a few jobs. I bought my first camera 3 years ago and film and photography is my full time job...so it is possible to bring in a decent income.
Luck and the people you know is about 80% of this business. Of course the more you get out and film the better. If you don't have a solid final product even the people you know will look elsewhere.
As long as you're loving it and having fun with it, keep at it and good luck!