In response to question 3 . . . I've tried using an
M-Systems IDE Fast Flash Disk (FFD) on a vanilla A1200 (with an A500 power supply), but the system wouldn't boot. It might work OK on a third-party IDE interface. M-Systems' SCSI products should work fine.
Others have posted about their experiences with compact flash to IDE adapters. A search for "compact flash ide" in the forums should bring up a few hits.
Trev