I have had multiple electrical problems which have all been very expensive and have put me off ever buying a peugeot ever again. I have had three main problems with the electrics.
Firstly 3 weeks after getting my car the distributer failed due to 'corrosion', result being a £400 bill.
The electric fan motor has packed up several times. Two weeks ago my ECU went and because is a SAGEM ECU it can't be repaired, but has to be replaced, costing me well over £1000.
Also a couple of days a go the wiring loom went up flames while I was driving along, not a nice thing! The cost is going to be again round the £1000 mark! Although I'm having the fault investigated as I've only had the car back since the ECU replacement and suspect that poor workmanship casued the fire.
I have problems with the central locking.
Poor fuel consumption for 1.8.
Exhaust gone.
Speedo fault.
Etc, etc!
Excellent handling and drive.
Comfortable ride.
Good creature comforts on this model.
I also have a 1998 Peugeot 306 1.8 GLX with 70,000 miles. Most of your problems are familiar to me - electrics, engine management etc etc.
One thing I cannot fault is fuel consumption though. 33 average and 40 mpg on a run!