Hi,
1. Yes it is by putting the CF card into an adaptor and then into the PCMCIA slot

(but see the answer to question 2)
2. Some accelerator cards can stop the PCMCIA slot from working. However, there is nothing to stop you from removing the card to do the transfer if that were the case and you are using a Workbench that doesn't require additional RAM

If I recall correctly, you can check if your PCMCIA slot is working by switching on your A1200 while keeping both mouse buttons held down. This will take you to the 'Amiga Early Startup Control' screen. Choose 'Boot Options...' and if you see CC0 in the 'Select Boot Device' list then you should be ok as CC0 is the PCMCIA slot

.
3. The CF card will be much faster

:pint: