No, the #50 Lynx bus will take you to Sea World cheap. To get from Disney to Universal by Lynx, it takes 3 busses and 2 hours. Not worth it unless you want a long adventure.
To get from Disney to USF, you have to take the #50, then another bus to I-Drive, then another one that drops you off at the Holiday Inn across the street.
Most people use a limo service.