Yeah, these cars really dont like it if you mess with the electrics.

I am still fighting with a broken clockspring which completly messes with my ESP/BAS and the spoiler.

Referring to the corrosion on the battery cable, I think the simplest trick is to spray some PW-40 (that oil I think) on it and it will stop corroding. Thats what Tazz did to mine and it works perfect. I'll have to check the cable again when I get back to AZ next week^^