Be aware that there have been threads in the past which indicate that the AI doesn't understand how to use limited-range weapons properly. See here for details:

https://forums.elementalgame.com/435793/page/1/

It's an older thread, so it's possible that things have changed.

Also, some other things you might find useful:

Quest Wizard - https://forums.elementalgame.com/417220/page/1/

E:FE Race Editor - https://forums.elementalgame.com/433305/page/1/

Note that I do not know whether or not either of these works with E:FE:LH - you can try them, and they'll probably give you a good start, but they might not work exactly as intended. (A note on the Race Editor - there was another thread indicating that it would not produce usable LH race XML, so if you make use of that one, compare the XML it produces to the XML for one of the base-game races and fix anything obvious, then fix anything else that causes errors when you try running the game).

Quest Master - https://forums.elementalgame.com/443956/page/1/

This one is for Legendary Heroes, so you might use it instead of the Quest Wizard for Fallen Enchantress.

You might also look in the modding forum mod lists, or search for helpful utilities or examples of the kinds of things you want to create.

As far as item creation goes, try this thread and the links found within it:

https://forums.elementalgame.com/446321/page/1

Well you can make the AI use limited range weapons if the effect is within a selectable special combat move.  An example would be the throwing knives effect.  This can be applied to bows by making them range unlimited but give the normal attack a hefty penalty and when at a certain range a special attack is usable every round that has no penalties.

For damage is there a way to make it a random number between 2 numbers. I know this is changing the core game alot but its something id like to try. Also i'd like to make some attacks scale very 3rd level does this game only recognise whole integers or can i say damage increases by .333 and every 3rd level it goes up 1 whole point.

It would appear from CoreSpells.XML that the calculations recognize division as a valid operator. Thus, even if the game doesn't recognize fractions inside the <Value></Value> tag, you could try making a weapon give a calculated damage bonus such as is used for Mana Blast.

Weapon damage already is a random number between two numbers. Specifically, it's a random number between 0.5*Attack*Attack/(Attack + Defense) and Attack*Attack/(Attack + Defense), where Attack is the attack value of the attacking unit (on a per-figure basis, not the collective attack value), and Defense is the defense value of the defending unit. If you want a more specific damage range, you could try

-<GameModifier><ModType>Unit</ModType><Attribute>CurHealth</Attribute><MinValue>-3</MinValue><MaxValue>-8</MaxValue></GameModifier>

which comes from the Chaos spell in CoreSpells.XML, and appears to deal a random amount of damage between the two specified values. I'm not sure whether or not you could put this on a weapon, though, except as a weapon ability such as Bash. If you do implement it as a weapon ability, be advised that the AI will not use abilities after moving the unit, so even if it would make sense to do so, it won't hit your troops with it on the initial charge if its units had to move to reach yours, and also that using weapon abilities doesn't trigger counterattacks.

mana will be used for mostly city and unit enchants. spells will be more or less abilities that the diferent classes will gain access to. i havent mod'ed the classes just yet. been focusing on items and balancing that. my next big goal will be implementing dnd monsters. when i get to the classes and spells, which i am sure will take alot of testing and balancing, ill start posting videos of the mod. hopefully this will make classes other than the mage be more useful.