If you're really excited about the limo, confirm that you're actually getting a limo. My DS and I booked a limo from Port Canaveral to DisneyWorld and although I booked the "limo" fair, it turns out we were not guaranteed a limo. We ended up in just a big car. Not really complaining, I didn't care too much. We just needed a ride to DW.
I booked a specific Limo just for that very reason. Chrysler 300 stretch to be exact. Wanted to know exactly what we were getting and not have something unexpected show up. I also did a lot of research on Limo companies in Orlando, and Happy Limo had a lot of great reviews for transfers to Port Canaveral. They have been very great to work with so far.
[edited as I apparently scrambled my thoughts]
It was nice and easy to take the train to DL from San Diego. We were staying in one of the DL hotels so it was just walking distance and we didn't need a car once we were there. It was a fairly quick/cheap taxi to DL from the train station in Anaheim. I recommend the higher class fare (hardly more expensive iirc) but remember that they give you a meal. We forgot, bought hamburgers on the train and then they delivered lunch.