Segmentation of the stands - Scouts, Teams, and the Public

[xXhunter47Xx]

I think it's really highly dependent of the venue, if it offers enough room.
The SD Regional was held at Valley View Casino Center (Sports Arena), and was commodious enough for just about what you described.
While power was still a problem, everything else was pretty much how you described it.
Teams mostly decided to sit in the center, obviously. General public could sit up in the higher seats if they wanted a view of the action.

Now think of a venue that would be much smaller than the San Diego Sports Arena.
Pits already take up half of your venue space. Then think about team members and supporting parents/mentors/sponsors that are there and want to view the action. If the venue is a high school gymnasium, you won't have much luck in that.

San Diego is lucky to have a large venue for FRC, but other regionals are not as lucky, so sometimes it cannot be possible to provide luxuries like voluminous and specified seating.
TL;DR
If the venue is large enough, it ends up being played out like this without guidance.
If the venue is small, there isn't enough space to plan it out like this anyways.