As far as the parades go, we always found that the train depot at the DL entrance is a good spot. We either watch on the sidewalk, or try to get a spot up the stairs (but sometimes they have this roped off - kind of "reserved" I guess). We also like this spot for fireworks!
In regards to getting around the park for rides...it depends on what you want to ride? Are you using a RideMax itinerary? If not, do you want to hit the rides in Fantasyland? If no on the RideMax itinerary, and yes on the FL rides, just get there at opening and ride the FL rides first, starting with Peter Pan, Dumbo, and Matterhorn, in that order.
We like to take less traveled walkways to get around...like the path between FL and Frontierland (go between the princess shop and the other shop across from it - can't remember the name, but there's a walkway right next to what used to be the door into the castle. At the end of that little curved walkway, turn right and there's another little covered walk that goes past some restrooms and rancho del zocalo and spits you out in Frontierland.
Sometimes we'll also take the back way from Village Haus Restaurant in FL to Big Thunder Mountain Railroad, because it's quicker.
Finally, if we need to get all the way across the park on a day with crazy crowds we take the train. It's just easier than maneuvering your group through thousands of people.
Hope that helps!