1) tank right behind firewall. you disconnect the fuel line between the tank and carburetor to fuel and de-fuel.
2) can't help with this one
3) yes. Ideally you get someone who has R/C experience to help you. These things are much harder to fly than full-scale.
4) Your radio will maintain control much farther than you will ever need. perhaps 2 km. always leave the antennae fully extended.