I'm guessing if you have a TV with built in Freeview and a seperate Freeview Plus recorder the set up would be as follows?

1). Aerial into FPR

2). Scart between FPR and TV

and that's it? Or have I oversimplifed/dumbed down the whole thing?

It is as simple as that.
If you want to use the tv's freeview receiver then you'll also need an RF cable from FPR's RF out to tv's aerial input.

So both can tune into Freeview.
- RF (Aerial) cable to Recorder RF In
- RF cable from Recorder RF Out to TV RF (Aerial) In.

Then a depending on the connectivity available from the Recorder in order to play back recordings.
- Scart cable from Recorder AV output to TV AV input
or
- HDMI cable from Recorder HDMI output to TV HDMI input