1: Part of the unit was pushed up against somewhere it couldn't go, so it instinctively moved away. Try and keep your units from mushing up against walls and cliffs.

2: The building in the middle of the castle is there purely for the sole purpose of getting in your way and making life more difficult. It has no benefits whatsoever in this game.

3: Archers are more accurate and can fire faster than muskets.. but muskets posess much greater penetrating power, and are cheaper, and produce a special negative morale effect upon the enemy; also they have more ammo which can be sustained over much greater periods of time due to the reduced firing rate. At least this is the way it works in THIs game. Arquebuses differ from muskets in the arquebuses have even lesser accuracy, shorter range, and slower reload. Arquebuses can be chalked up to almost totally useless.

But Bow vs. Musket is usually a pretty close fight, they both have their special advantages tho. Also note that Muskets are a bit harder to use correctly, and they have many more LOS issues which can be a problem when dealing with trees or steep hills (this is just a dumb 'feature' of the game).

3: Teppu Ashigaru (i.e. gun Ashigaru) are almost entirely worthless in combat. Archers can hold out sort of ok (more so in the original than in the x-pack), but Teppu will get slaughtered.

You can maybe remember it roughly as Yari Samurai beats Samurai Archers, Samurai Archers beat Yari Ashigaru, EVERYTHING beats Teppu Ashigaru.

Hope that was helpful.

Matt