No, it was not.
When the park opened, it was divided into 2 sections:
1, The "theme park", which was The Hollywood Blvd and Echo Lake areas.
2, The "Studios" which was the tour areas (did you ever wonder why the studio arch is in the middle of the theme park?....this was the entrance to "the studios".
The only place you could wonder at the studios was the Animation Courtyard area, which is where You could either board the Studio Tour or do the Animation Tour. Playhouse Disney was a resturant (Soundstage Restaurant) which was using the sets from the movie Big Business. Upstairs, there was a bar called the Catwalk. The Voyage of the Little Mermaid I think was a ________ Tracy show, then a muppet (live action) show....I dont remember.
The security gates you see throughout the park were actually always manned and down....there is one just past the Backlot Express, another near the exit to the Great Movie Ride.
By late 90, or early 1991, the majority of the park was opened to the guests.....the park was just way too busy, and crowded. MGM went on a major building spree, opening Star Tours, Muppetvision, a bunch of restaurants, and in 1994, Sunset Blvd.
I think 1 reason that MGM has sucj bad flow is that the park is completely different than it was built to be. It was supposed to be a working studio, and it was not supposed to get 10+ million people per year, as it was in the early 90's.