I would like to visit Neuschwanstein Castle. However, I don't know when I will be there, so that I am unable to book a ticket earlier. Is there any daily visitor limit there? If so, after reaching this limit, Is it possible to get there and see it from outside (from its court, like in Vienna's Schönbrunn) without buying a ticket?
If you travel during summer holiday season I would say forget it. All the tours are reserved, I was there in March (the off-off season) and they were doing a steady business. The outer parts are not ticketed, and the other castle (Hohenschwangau) is less busy.
It is definitely worth the trip, I would say plan your travels around the ticket date, there are not all that many other attractions in the area so those destinations can be flexible.
Just in case you don't get tickets for Neuschwanstein: There is another castle nearby in which King Ludwig II (who built Neuschwanstein) grew up - Castle Hohenschwangau (http://en.wikipedia.org/wiki/Hohenschwangau_Castle).
It might be a good alternative if Neuschwanstein is too crowded - many locals recommend it as the better alternative (better guided tours, the rooms are closer to their original states than in Neuschwanstein, etc.).