the brackets represent the change in the count. outperform and underperform are euphemisms for buy and sell recommendations after the 2002 financial regulations related to the dotcom crash. the value of such information is dubious however.
Warren is making jokes out of analysts through out his entire life. I don't pay any attention to their recommendations or warnings. In fact , a warning might be a sign to - buy.
Yeh I think studies have shown stock anal tend to be slightly wrong over time . Atleast the public" ones.