There were walls. Just most of the time invisible and funneling you towards the path to the adjacent zone.
I agree with some of what you said though, OP. EQ was a very special game for me at the time and will always be dear to my heart. But that said, I think a lot of it is hazy nostalgia. I actually installed an original Eq server emulator project awhile ago (It was EQ pre-Luclin) and wanted to bang my head against a wall.