Taxi job seems useless, i see someone rarely playing as a Taxi Driver.
There are job missions for medic, firefighers. My suggestion is to add some Taxi Job Missions like medic, firefighter job missions.
Job mission like Singleplayer San Andreas.
Intercity job missions Pick a NPC Actor from LS and Drop him to LV/SF, etc...
This could add some new feature and players could try this.