I talked about this in one of the many "the barn sucks" threads.
The widened concourses can't really happen at least on the north side, but this is what I'd do.
Eliminate all bench seats except the student section. Put in nice chair seating, and space it out better.
Put in actual urinals.
On the ends in the upper deck, see if there's a way to build some kind of party deck/suites and eliminate those as seating areas.
Then, on the south side, build out a large concession area with modern options, modern restrooms, nice seating areas with monitors and such - think of the club level at the Xcel.
At the very least, they need to visit Butler and the University of Washington and see what they've done with their equally ancient buildings. Especially Hinkle Fieldhouse at Butler. You can restore the Barn, but you need to do it right.