With regard to the weather we've 'enjoyed' over the past 8 weeks, it's difficult to imagine why anyone would choose FL for a relaxing break - but the reality is that recent hurricanes are very, very rare and generally central Florida is untroubled by these severe storms.
Personally, I like the Rolex at Daytona - it's a great season-opener at an awe-inspiring facility - even though the race is nothing like it used to be.
Sebring is a half Le Mans - only you actually get to see the cars. The venue, albeit steeped in history, is basically a disused airfield in the middle of nowhere.
As stated above, Sebring is the more important race - but the superspeedway at Daytona is a wonderful place to visit - let alone take in a 24 hour enduro.
Kennedy Space Center is about 40 mins east of Orlando, Daytona beach is 1 hour 20 mins north east and the 'attractions' are 20 mins south west. Sebring is an hour and a half due south of O'town.