tell me what i need to know about SunPass...

[tkldisney]

If you have rental car that does offer e-pass option and you have your own transponder or mini, your pass overrides rental car one, you will not be charged daily charge by rental car co.

 

[KINGBOBOFTHENORTH]

What if we wanted to drive on over to Daytona or down to Tampa from WDW? Any idea on how many and how much the tolls are around those places?

From Disney to Daytona Beach the route is I-4 so there are no tolls.
From Disney to Tampa the route is also I-4 so again there are no tolls. There are a couple toll roads and bridges around Tampa but it seems unlikely that you'd encounter them on a trip from Orlando.

BobK/Orlando