To go onto the problem of the blown fuses, you say a fuse in a fused switch for the fan blew?
And the fuse for the outside line?
Can you explain what the outside line is?
I can't see why the fuse for the fan should blow. The only possibility I can think of is that the supply for the fan is fed off the feed to the outside light and went off when you short-circuited the wiring.
There appear from your description to be 5 conductors in the cable: 2 "earths", live, neutral and black wire.
It is crucial these are identified.
If (as I think someone previously mentioned) you say there were 2 earths, it is possible you have confused the yellow as an earth wire and connected it to the bare conductor, which is the actual earth wire.
In the cable, I saw in the pictures are: Red, Yellow, Blue, Black and a bare CPC (earth).
Which of those did you connect as live and neutral?
Is there an override switch anywhere so you can turn the light on permanently (rather than just via the passive)?
My guess is that in the cable there is a live, a neutral, an override wire and an earth and a spare. But you will need to either look in the passive or at the origin of that cable to find out which colour does what.
The picture you have taken of the wires connected to the PIR is of the inside of the adaptable box lid. It doesn't show the wires where they connect to the PIR terminals.
If you can take a piccy of the wires where they connect to the PIR, that would be a help.