With a Sawzall.
YES.
.035
either a dead starter or a bad ignition coil would be my guess
Your best bet is to hire a locksmith.
VATS system
autozone or napa
The voltage regulator on a 1989 Chevy Camaro is inside of the alternator. If you are having issues, such as flickering lights, you might have to replace the entire alternator.
$48 for a remanufactured. both motors that year share the same starter.
Nothing, there is no such thing as an 89 Camaro Z28
You didn't mention what engine you have but, if you follow the positive battery cable from the battery, it will lead you right to the starter.
There are many places where one can purchase an 89 Camaro. One can purchase an 89 Camaro at popular on the web sources such as eBay Motors and Auto Trader.