For your horn and cruise control problems, check on the 'clock spring'. This is a common problem with some Ford cars, and if it breaks, will disable everything controlled through the steering wheel. Its a thin spiral spring that maintains ground contact for the electrical system when the steering wheel turns.

-Mark- '99 Mystique LS, totally original (including the original water pump and the premium stereo)! Bought new in December 1998 for $21,000. 208,000 miles