Cool car and review! My buddy in high school had a 78' Grand Marquis 2-door with the 460, which is fairly similar to this including the abysmal MPG, and a ride like floating on clouds. We'd load up 7-8 people and it was a blast.
Power steering in those days, was about reducing as much "driver effort" as possible. Remember, cars used to have manual racks, so cars like these, were very luxurious. It might not feel safe vs. driving modern cars with more direct power steering, but in reality, there's less room for error, and body sway would have put you in a ditch if otherwise
Everything pretty much had the foot switch for the brights. Had a 78' F100 in High School (90's) and I was clueless about it. Thankfully a buddy was wiser than I. The trunk auto-catch was way ahead of it's time though.
If looking to do another odd, very pricey Caddy for the time, consider a Cadillac Allante. For quirky, Buick Reatta. Reatta had a precursor to modern touch screens, was 2 seater, etc. The Allante was hand built by Pininfarina, then shipped to the US where it was mated to engine/chassis. They also cost $55-65k depending on year/model, which was ridiculous in the late 80's/early 90's (considering a Porsche was in the same range). I've actually driven both of these when I worked at a car lot about 17 years ago. I actually liked the Reatta better :/