A lot of the red abilities seemed useful in theory, but I found that playing that was the best way to consistently lose the game. Undertuned, maybe.
The thing with the briefcase is that you have to weight the payoff against losing access to the excellent extra interest item forever, and it does not compare favorably. If the game gets longer, that prospect will be even worse. However, I did not realize that a full-yellow run was even viable in this 8-game format, since it's so hard to get the opportunity translate money accumulation to any real advantage when the pieces you want to snowball into are so rare and slots are so expensive. It does make sense to have the briefcase as a pivot, since it would be the lesser of two evils.