It has nothing to do with holding an item... its the ability to
equip such items. You should be able to store such items in your bank until
the time in which you have proven the ability to use such items. They
already have a form of this now. Some weapons, which have a magical effect,
will not cast its spell until the bearer has achieved a certain level. If
you wish to make the game a tad bit closer to reality how could you expect a
low level squire to have the ability to skillfully use the same weapon as
someone who has achieved the Master skill level for 2H slash.

Lance