I want to get started in this hobby and always have, but I am one a very limited budget until I can get out of college. I have gotten the plans for the spadet and am wanting to start building. Now time for some questions.

Do I need to flash or can I use the scotch brite, mineral spirits method?
Do these methods need only done where the glue will go?
I am set on getting a 4 channel radio, but is it OK to buy a used one on ebay or something?,
I would like to be able to switch it into an electric flyer someday, if the desire hits me.
What about a used engine?
Any brands or models on the radio and engine?
I am an engineering student so the building of the spadet looks fun to me. The airplane I am pretty set on, but everything else is in the air.

Thanks for the help