Without drivers, add-on cards like CyberGraphics would be useless.
Yeah, but Windows doesn't know the hardware is installed until the driver is available. Actually, Windows knows "something" is there. It just doesn't know what it is until it has a driver. Autoconfig lets the system be fully aware of the hardware without requiring additional software to enable it.
Application software will almost always be necessary regardless of the OS. App software and drivers are two different things.
IRQ is not an issue in modern X86 PC hardware and OS.
It shouldn't be, and usually isn't a problem. Depending on certain factors, though, IRQs can still cause problems.
In X86 PC land, increasing main memory capacity and installing faster hard disk benefits more than installing faster CPU.
For good or bad, Amigas don't exhibit this behavior. Increasing memory by itself won't make the applications run any faster. It just reduces that particular system's limitations.