I believe Workbench 1.3 should work fine with Kickstart 1.2. IIRC the main difference from 1.2 to 1.3 was something related to hard drives, shouldn't be a major issue with a floppy based system.
You haven't said which Amiga models you have, but with Kickstart 1.2 I'm guessing A1000, A500 or A2000 models.
You can't use a CF card since the A500 does not have a hard drive controller. You'll need extra hardware, etiher
old or
modern.
An A2000 may have a hard drive controller installed, you'll have to check inside. Though Kickstart 1.2 would lead me to think that you haven't got one.
The A1000 is the trickiest to upgrade in any way.
As for testing the keyboard(s), ctrl-amiga-amiga should reset the computer. Probably no way to test them more thoroughly without a bootable floppy. Even "dos" needs to be loaded from somewhere
