2. Weapon Mastery- After taking some ideas from internet forums and OD&Dities issue 7, I came up with these changes:
2.1 Starting Ability
All characters are considered to have Basic ability in all the weapons their classes can use. (Magic-users do not get the expanded weapon selections in the Cyclopedia) A character attempting to use weapons that their class cannot use does half damage. (And, in the case of some classes like cleric and druid, may suffer other ramifications as well) A character's first weapon slots let them become Skilled, and so on.
Under my new system, characters do not gain any Mastery slots at 1st level. Instead, starting at 3rd level, Fighters, Dwarf Warriors, Elf Adventurers, and Halfling Wayfarers get two slots (which must be spent on different weapons). Dwarves must use one on some type of axe or hammer, Elves must spend one on some type of bow, and Haflings must take the sling. All sub-classes of fighter get one slot. Characters must seek training as normal to spend this first slot. From then on, the classes listed above receive new slots per the the Cyclopedia.
All other classes receive their first slot at 6th level and gain them normally henceforth.
2.2 Hit bonuses- These have been halved, such that characters receive +1 at Skilled, +2 at Expert, +3P/+2S at Master, and +4P/+3S at Grand Master.
2.3 Deflect- In order to Deflect, the character must make an attack roll and beat the result of the enemy's attack roll. (Rather than make a save as described in the book) A failed roll means the attack hits normally and the Deflect is used up. Note that some very large opponents or some attacks cannot be deflected; a dragon's tail slap, for instance, cannot be deflected by any human-sized weapon.
I want to reiterate that I'm using Weapon Mastery rules because I'm running a game for a bunch of martial arts students; if I know them like I think I do, they are going to want some kind of system that reflects weapons techniques and tactical choices.