I think Dwayne pretty much hit it on the head ...
From the rulebook :
Using Weapons
Without purchasing any skills, any character with at least 1 physical stamina can use a single small weapon, such as a dagger.
In order to use any other weapons or styles you must also have the skill Basic Combat.
Once you have purchased the Basic Combat skill, you may select one Weapon Type or one Weapon Style to be proficient in for each point of physical stamina you have. Certain Weapon Types or Weapon Styles may require you to have a certain minimum number of physical stamina before you can select them.
If you have 10 physical stamina, you may use all weapon types and all weapon styles.
You do not need to select all your proficiencies immediately. However, during an event you can only use the proficiencies that are listed on your character sheet at the beginning of the event. If you decide you want another proficiency, you cannot start using it in the middle of an event even if you have physical stamina points remaining for which you have not yet selected a weapon proficiency. Proficiency in a melee Weapon Type does not let you use a two-handed weapon of that type without proficiency in the Two-Handed Weapons style, with the exception of the Staves type, which may be wielded two-handed with no further proficiencies.
The Weapon Types are:
Axe, Bow, Mace/Club, Crossbow, Firearms, Hammer,
Sword, Spear/Polearm, Staff, and Thrown Weapons
The Weapon Styles are:
Shield - You may wield a one-handed weapon in one hand and a shield in the other. Prerequisite: Physical Stamina 5.
Florentine - You may wield a one-handed weapon in one hand and a short or small weapon in the other. Prerequisites: Stamina 3.
Paired Weapons - You may wield a one-handed weapon in either hand at the same time. Prerequisites: Florentine, Physical Stamina 5.
Two-Handed Weapons - You may wield melee weapons which require two hands to wield. Prerequisite: Physical Stamina 4.
Using Weapons Skills
For all skills used through a melee weapon or thrown weapon, the Stamina cost is expended when the strike connects and is acknowledged through roleplaying or negated with a defense. For all skills used through a packet bow or a gun, the Stamina cost is expended whether or not the strike connects, unless the strike clearly hits but is not acknowledge through roleplaying or negated with a defense.
From Chapter 2 - Isles Rules
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Thrown Weapons work just like all other weapons.
You may spend stamina to increase damage, but if you do not - they do "1" point of damage if they hit the target.
You may use called attacks, if the skill allows & if the weapon has the damage capacity to make the attack.
The assigning of weapon skills on character cards is something we have never done -
perhaps that will be enforced more in Isles 2. I don't think anyone has abused the proficiency system, at least not badly.
Note, there are 10 weapon types, and 4 weapon skills. Each costs a "slot" in the limit you may choose based on your physical stamina score. If you have a "10, you get the bonus of being able to use "all" of them - all 14, not just 10.
-Chris