I support Frisk, Forewarn, Clear Body, and Trace for reasons previously mentioned many times. A few other abilities that have been mentioned that I'd like to bring more positive attention to are Sticky Hold and Natural Cure.
Sticky Hold would be nice for scouting Trick users (and Knock Off users, to a lesser extent), as everyone knows a <insert your favorite wall> with a Choice Scarf is something to be avoided at all costs.
Natural Cure would be good so that CAP7 wouldn't have to worry about status when switching in to scout. We'd have to give it a more ominous name though, as "Natural Cure" sounds rather pleasant and not at all spooky or metallic.
A few abilities I'd like to bring more negative attention to are Speed Intimidate (or "Petrify" as has been suggested), and Levitate
Speed Intimidate would, I think, be a broken ability. CAP7 would be an instant counter to any sweeper that requires speed to do its job (i.e. 95% of them, notably Dragon Dancers). The Choice Scarf would become much less popular as all your opponent has to do is switch in CAP7 and the positive effects of the Scarf are nullified. Nothing should have that much countering ability.
Levitate would be unacceptable if CAP7 is going to have defensive stats. It would have 4 immunities, two of them (Fighting and Ground) being very popular. If CAP7 is going to be offensive, with low defensive stats, then Levitate would be OK, as it would only ensure safe switch-ins, but CAP7 would still be able to be KOed by neutral moves.