The difference between a Howitzer and a normal cannon

I found this in the official manual on the official forums:

Line Infantry

Line infantry was the most common Infantry type in the Napolenic wars. Line infantry are usally equipped with a bayoneted musket and sometimes with a small sword referred to as a “butter knife” or “sabre briquet”. Line infantry have medium shooting and melee skills and are a good all rounder troop type.

Light Infantry

Light infantry are light and fast moving units that possess good shooting skills. Light Infantry is equipped with an unbayoneted musket and a small sword for melee combat. Due to their good speed and accuracy; they are especially useful for flanking enemy lines and supporting fire. However, light infantry is at a disadvantage in melee and should thus avoid getting to close to enemy lines.

Riflemen and Jaegers

Riflemen are light and fast moving units with good shooting skills. Riflemen are equipped with a highly accurate but slow to reload rifle and a small sword for melee combat.
Due to their high shooting and running skills, riflemen are especially useful for sniping enemy officers. However, Riflemen are at a strong disadvantage in melee combat and should avoid getting close to enemy lines.

Other than the differences you listed (price and safety), you party heals faster when waiting in a fort/town or village with a manor. The amount of experience granted from training is solely determined by the skill of the trainer and nothing else.

There is 1 (very minor) drawback to waiting in a town/fort/manor, and that is you can't open the dialog to 'take an action' and select a new book to read.