As far as I know , the magic atk is not affected by the magic bonus you have , so its best to use it with melee armor (if you are fighting against ranged/melee) and with ranged armor (against mage based attacks) (there is 90% chance of the magic bonus not affecting the atk theory is wrong ..)

 

The question is :

 

Since the weapon gives slash and ranged bonus .. It should be affected by the slash/range bonus you have right ?

 

And any idea what is the max dmg ? (in other words how hard the ranged hits compared to a type of arrows/bolts , same goes for melee ...)

Don't know about ranged or melee, but I can hit over 20 (i believe my max is 22, but it has been a while since I used one) with the magic attack, and I believe it is faster than normal spells. But the XP for magic sucks, because you don't get any "casting" XP like you would for a spell. Something Jagex needs to fix, IMO, by upping the mage XP from salamanders to 4 per damage, instead of just 2.

I max 25 with 106 mage (wolpertinger) and +15% mage prayer, the mage prayer DOES affect the max hit. Magic bonus affects accuracy tremendously, you will splash like crazy anywhere but barrows with full melee armor on. I would assume that range\melee bonuses affect their respective attacks, but I haven't tested them extensively yet.