Check on pre re/item_db or re/item_db for the item you mention, find Job and Class option and see if your Job are capable of equip those weapon. Read Doc/Itemdb for class and job info.
ID,AegisName,Name,Type,Buy,Sell,Weight,ATK,DEF,Range,Slots,Job,Class,Gender,Loc,wLV,eLV[:maxLevel],Refineable,View,{ Script },{ OnEquip_Script },{ OnUnequip_Script }
For element option, you can refer on doc/item bonus. Read those file, it helps you how to add element to weapon. the script later on will be put onto Script option. Element need script to run. So it is important to read item bonus.txt and understand it.
Example Element Script : bonus bAtkEle,Ele_Holy; < ----this will grant item a Holy Element Attribute when Attacking.
Where to put this? >> { SCRIPT } .