The subject line is a little misleading since the "2005 Malibu Classic" is a totally different animal than the "2005 Malibu," i.e., it's basically the 2003 Malibu chassis with the Ecotec 2.2L. It so happens that I once looked at a similar problem on the 2003 Malibu and kept the notes. On this generation (Classic included) the ignition switch in RUN switches in the battery voltage from the 40A Ignition Switch fuse in the engine compartment fuse block to various circuits you mentioned:
In the passenger side instrument panel fuse block:
Climate Control System fuse -- for HVAC blower at intermediate speeds
Cruise Control fuse -- also Cruise Control Switches fuse
Power Windows circuit breaker
In the engine compartment fuse block:
Climate Control System fuse -- for HVAC control assembly
Canister Purge Valve, PCM, Exhaust Gas Recirculation, Heated Oxygen Sensor fuse -- also DRL relay coil and Rear Defogger relay coil
The last fuse is emission-related and thus will light the malfunction indicator.
You can check the voltage levels at the above junctions while jiggling the key with the key ON, engine OFF. Look for unstable or low readings (compared to the 40A Ignition Switch fuse) in which case the culprit will most likely be the ignition switch.