RE: Gas Tanks and Engine
You should be able to find out most of the directions in the instructions for the engine and model. If you can't find them, there are many sites that allow you to download the instructions. I know towerhobbies has many airplanes you can download the instructions to. Kyosho too.
And... it's good to have someone check it out before the maiden even though it shouldn't be a problem as long as you can get through the running in. On that note, please check out the breaking in procedures here... there is a very different school of thought in terms of breaking in an engine than what is printed in the instructions