seems to be all fixed; the regional senior tech for Kia came by and supervised checking all the connections in the plugs and wires in the affected systems(AEB, cruise control, braking) and they discovered _one_ connector/wire that was not making good contact. some sort of contact enhancer was used and that seems to have resolved the problem. none of the subsystems individually had any fault codes in memory.
the really good news, for all current and prospective owners, is that all my problems are 'in the computer' and therefore accessible to all Kia dealers so if anyone else has weird braking, AEB, CC problems, i have already experienced it and the fix will be quicker for you than me!
SO, handled well by Kia, local dealer service, i was given a loaner rental car, and i got my car back(goodbye ford fiesta!)