Getting there was not too bad, because they have staggered entry times. Getting back is a nightmare. When going traffic backs up about 9miles from KSC and you think you'll never make it. However, they check credentials before the bridge so this isn't as bad as it first seems. Once you get to the bridge you get in pretty quickly.
Last time we went I got through for the tickets at 9:40 and the causeway tickets were gone. I asked if they were still available for annual passholders and we were able to get the "good" tickets.
If you do get causeway tickets, you go out there a few hours before the launch and there is nothing to do out there, but bake in the sun. My kids took their Gameboys (these are allowed). We also took a backpack with plenty of waters(some frozen which were thawed well before we left). They do sell drinks, chips, burgers and hotdogs.