Well you also have to consider that ninja hasn't even been out for a week. You will commit a lot of things to memory with more playtime just as people had to do with the other jobs in the game. It wasn't uncommon for people having a difficult time keeping up with all the buffs, debuffs, DOTs, and CD timers on monk. Bear in mind I'm not trying to say ninja is easy or anything of the sort just that things become easier and more natural to you with time. In a month you might find ninja about as easy to manage as monk, or you might still say it's just as hard. Just a few days of play time isn't much time to make a judgement on how difficult something is to play because it will still be very new and different.