I'm only upto Chapter 3, but the camera is the most annoying thing ever. And the projectile shooting enemies are the cheapest. Otherwise, its not that difficult, but I heard the difficulty shoots up in the middle of the game. I'm trying to get through the game without using healing stuff except for the save points and so far I'm succeeding.
The battle system has improved, but the enemies are much cheaper.
I find the lunar staff good for fighting crowds, but I also use the dragon sword a lot.
Basically, when you turn a corner, throw shurikens to locate enemies/slow them down. Keep doing the reverse wind + jumping away from crowds, while throw shurikens to make them break up the cluster. Use flying swallow to hopefully kill one, or follow it with a quick combo, get away and repeat. Once you have one dead, get a way from the group and start charging up your UT, and once one gets near, unleash and repeat for a while. I usually lead enemies to a wider area for fighting because they usually try to ambush you in narrow locations.
As for bosses, just keep retrying until you find a good tactic and you can get through without healing. I'm playing on warrior btw.
Oh and the fiend's bane bow rocks. Now I can take out those damned flame arrow shooting ninjas.