At POP I actually wouldn't suggest a preferred room. There are buildings that are not preferred equally as close to the main hall as others.
Possibly, but you can't guarantee for sure that you'll get in one of them. I wouldn't want to be in the 80's/90's, they are too far from the bus stop and food court for us. I still usually have to ask to change rooms even with preferred, and feel that they are more willing to do so because of it. (We like a room facing the courtyard or pool cause we decorate our window!)
My tips:
1) Do not just walk up to the characters you see. No. Don't do it. There is a line. You may be distracted or oblivious, but its there. Do not send your small children to run up to Mickey because the line looks too long. I saw this more than once on the trip we just returned from!
2) Do not stop in the middle of a path where people are walking to do anything; adjust your stroller, adjust your backpack, adjust your undies, no! Not unless it is a medical emergency! Please move you and your family off to the side to argue over the map, drink water, have a friendly conversation, whatever it is. Especially in the crowded times. It can get to be like an obstacle course or a game of Frogger hopping from empty spot to empty spot around people who are just standing there, not moving.
3) Rain hood for the stroller in summer. Don't even question whether you'll need it! Do put it down whenever you go on any attraction, even if its sunny with not a cloud in the sky when you go. We went in Finding Nemo the Musical and it was bright and sunny, came out, it was bright and sunny. Somewhere in the 40 minutes, it had rained ferociously for probably 5 minutes, totally soaking the stroller the one time I did not use the rain hood. Unfortunately it was an Uppababy G-Luxe, cushy to ride in, and like a sponge with water. A plastic mesh stroller like a Maclaren Volo would be better.
4) If you are traveling alone with your kids and the kids are ages 8 and up, a cell phone or walkie talkie for each is a NECESSITY. I wavered on this before departing on our trip with my 2 year old and 9 year old. I was so grateful that I had decided to go ahead and get a prepaid phone for the DS9, there wasn't an hour that went by our whole trip (while at the parks) that I didn't use it to contact him. He often got separated from me and the stroller due to the crowds (and him moving slowly, not watching where we are going or getting distracted). If we had not had a way to contact one another, it would have been a complete disaster. It was a lifesaver. For younger children, a dog tag engraved with their name and your phone number on a chain that they wear around their neck, inside their clothes (or the Safety Tat mentioned) ...is a must. It is all to easy to get separated and can waste valuable time trying to get back together, not to mention the fear and anxiety for both parent and child.