I've been having cold starting problems for a while now. Replaced battery a while ago (second hand) and it seemed to have cured the problem for a bit but now I'm experiencing similar problems again, with some added bonuses..
I use the car at least twice a week but every time I go to start it, I have to use a boost pack. I haven't had a chance to test the battery with a proper tester yet but something tells me there's another issue killing my batteries..
Plugged it in the other day and a load of permanent engine fault codes:

* 12 - AFS
* 21 - Coolant temp sensor
* 23 - Cam position sensor
* 24 - Speed sensor
* 25 - Barometric pressure sensor
* 31 - Knock sensor
* 41 - Injector
* 53 - Ignition signal 3
* 61 - Elc 4AT comm.
* 36 - Ig Adj Termi

These did not clear even after battery was disconnected for over an hour.
Other symptoms that may or not be relevant:

* Occasional erratic idle
* Starter motor struggles to engage (single click) even with boost pack
* Every time I get out of the car, I get a static-like electric shock and this is getting rather annoying now

Has anyone experienced something like that?
The chances of all these sensors failing at the same time are quite slim - does anyone know what do all these components share? Could it be a common earth/relay/wiring section or ECU? Or could it be down to a duff battery?
I haven't got access to a wiring diagram so any suggestions welcome