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What extra things would I need to finish an ARF?
RTF would mean charge the batteries and add the fuel. It is a misnomer as there are pre-flights in ANY aircraft when flown responsibly. After you open the box you should at a minimum check the center-of-gravity, check the control surfaces, break in the engine with three tankfulls before trying to get airborne.
I've never actually seen a glow fuel powered RTF, but I'm sure they exist somewhere. For an ARF you will need a single-edge razorblade (unless you have a #11 X-Acto knife), a small Philips head screwdriver, a set of pliers (a selection of pliers is better), a small quantity of 30 minute epoxy (hardware store variety is OK), probably some thin CA (hinges), some white glue (Elmer's or carpenter's glue), possibly some masking tape, a sheet of #220 sandpaper and a yardstick. Most other construction items are nice but optional. It also depends on the model. Some are less ARF than others. You might need some metric allen wrenches, but usually if you need one it will be included. You might need a drill and selection of small bits. A large, well lit flat area that you can use for a couple days is a big plus.
You'll also need fuel, foam rubber (to pack the battery & receiver), #64 rubberbands, a glo-starter, glo-plugs to fit the engine and a chicken stick or electric starter to get her running.