lore is very reliable and useful if used properly. The only thing that lore won't reliably id is average damage of a weapon. But you can get a fair idea of that using lore.

I can use lore reliably to work out any spell effects on an item (few repetitions and see what comes up regularly), any stat modifications including hp and mana etc (100% reliable), flags (100% reliable), armor (100% reliable), value etc.

What exactly is it that you can't use lore to find out? Weapon damage average is one. Anything else lore can do for you.