It is a very easy drive from PBI to VB on I-95. Plan on less than 90 minutes. Or, purposely take A1A and enjoy a leisurely drive through some interesting upscale areas.
DSIL lives about 10 minutes away from Vero & flies into West Palm all the time. I htink West Palm to WDW would be 60-90 minutes...not quite as close as orlando, but certainly do-able.
Daytona Airport isn't bad either. Sanford Airport too, but neither daytona or Sanford are really popular.