I think the beach at the Poly is your best bet for Wishes, but if you would like to try to see Illuminations, you can see some of it from outside any of the BoardWalk area resorts.
I would vote for viewing Wishes from the Poly! And, there is the Electric Water Parade that goes by the Poly each night (weather permitting ) around 9pm too, so that is an added bonus!
Yes! MY WIFE and I travel through Orlando many times and we always time it to Wishes. After a certain time in the evenings you dont even have to pay parking. We drive to the MK lot, drive to THE FRONT (YOU'LL FIND FRONT SPOTS FROM PEOPLE WHO HAVE LEFT!) , get out and walk to the Ferry Landing and watch Wishes. the music is piped in too so you can even hear the music. No charge!