Welcome to the forum. I'm sorry you rolled your new rod... but your experience is a good example for anyone who purchases a car that has been built by someone else. Caveat Emptor..... may the buyer be where. Buyers need to completely familiarize themselves with all aspects and idiosyncrasies a car might have, and if something is wrong or not to their liking they need to fix or modify the car before just charging off to the local car show. I'm not by any means saying you did this... just that your experience is a good example to novices as to what can happen.
Yes, if there isn't some kind of pressure limiting modification done to a Chevy pump when hooked to a Ford rack, the steering will be a bit "twitchy" but this alone won't cause an accident. There are two or three different solutions to this problem and they all work well, although to different degrees. I always use the pressure spring to lower the pressure while others prefer a valve to do the job. Both work but which one you use is based on personal preference.
Again, sorry you had this problem and I hope you enjoy your ride.. once it gets back on the road.
"I don't know the key to success, but the key to failure is trying to please everybody." - Bill Cosby