1. Instead of a massive. monolithic 1982 Epcot-pavillion-scale building in the middle of the park, it could have looked like 2-3 side-by-side industrial buildings, with mixed heights/materials (some stucco, some corrugated metal), so it plays better with everything around it scale-wise AND establishes a themed "neighborhood" evocative of the industrial zone LA, home to F&F car culture. And a giant building that looks the same from all sides will make the park feel smaller while many smaller buildings that look different from different sides will make the park feel larger, which is important in the overall perception of the park's size/value proposition.
2. The issue is not the intellectual debate or the long-ago history of the land (tourists aren't on these forums and don't know or care), it's how does USH compete with California Adventure (which was a parking lot, if we're managing expectations based on land history...which I'm not; I'm relentless in critiquing DCA's power lines). The issue as I see it is that these two parks are head to head for "second theme park day" in So. Cal. for tourists. People will judge all the attraction offerings, convenience, food/bev, pricing, and "quality" of theming and some will perceive one park as better and another worse. For some, better means more immersive and transportive. I think USH is leaving some money on the table here, unnecessarily. Immersion and great sight-lines do not necessarily cost more money, they usually just require some strategy/creativity.