Why?! Why?! Why!!! Why is MooShu so long! I mean seriously! And it's quite hard! Erg!!!
Mooshu never seemed that long to me at all. If you're having issues with Mooshu, you may want to go back and do some side quests to level up. And Dragonspyre, which is next, is much longer and even more difficult...as are the worlds after.
Mooshu just seems long because everything requires so much walking. It can be finished in a single day if you have the time to put in and know what needs to be done. It also really depends what school and level you are when you reach it. If you are having trouble at your current level, go back and do side quests or go work on Grizzleheim and Wysteria to take a break and level up so you are more powerful.
make a storm character, then Mooshu will only take 2 1/2 days to complete. I have a life character and Mooshu was Very long to me. Don't worry, play for about 4-5 hours a day and you'll be in dragonspyre.