thats not good ! what does that sequence do ? disable the immobiliser ?
and that doesnt explain the keys and central locking not working, checked all the fuses ?
do the wipers, interior light, indicators work ?
check the central locking fuses, I had a clio recently which would not release the immobiliser, central locking didnt work, indicators, wipers, interior lights, looked just like the Bsi (bcm) was knackered but turned out to be the central locking was not sending a signal to the Bsi/ bcm
took me 3 days to find it, i visually checcked the fuses and didn't see it blown, then i used the multimeter
a lot of things are linked via the bcm, the transponder sends a signal to the bcm which pings the ecu to release the immobiliser, this has to happen in a certain time, hence you cannot alter the loom