All engines are bad on the environment, they exude used chemicals once fuel is burned. But with technology progressing as it is there is less impact on the environment today than there was 20 years ago.
There are many different sites that sell rc plane engines. Some include: http://www.hobbypartz.com and http://www.towerhobbies.com/. There are others if you look around.
It is best to get flying lessons so you do not destroy an RC airplane because it is difficult.
The best brand for RC airplane parts are Blue LiPo, Gens Ace, Sky LiPo, A123 Systems, Exceed TX and FlySky Airplane/Heli TX. They were all reviewed as the best brands of RC airplane parts.
RC Airplane simulators are similar to video games. You put a CD into a computer and it brings up an application that allows you to simulate flying a real airplane.
Same guy that invented RC Cola.
There are several places you can look. It does depend on how high of a quality of an RC airplane that you want. Check out this place. www.nitroplanes.com
A RC simulator is a combination of computer graphics and mechanical mechanisms that allows you to simulate the actual look and feel of flying an airplane.
Yes many people swap engines in RC Cars. This can be done. This site teaches you how to replace the engine in your RC Car : http://www.rccaraction.com/
The cheapest micro rc airplane I could find was the Rc universal Biplane Flatout 3D ARF 30.6".Which cost $32 from Great planes or $39 from amazon.This is the cheapest RC plane I could find on the Internet
A RC airplane is a radio controlled plane; it works with a radio communication, transistor and it's generate by a computer. The mechanical behind is the same as every operation machine.
You can buy inexpensive rc airplane batteries online at www.all-battery.com/rcairplanebatteries.aspx. This is a great store to find all cheap batteries online.
You find RC car engines online at many different retailers. A good retailer to check out is eHobbies. There are many different models of engines to choose from. Here is the store: http://www.ehobbies.com/