WoW models and other questions

[Drain]

So I want to ask you some questions about doing some things so
1:How can I use another animation of an object like (I have a model of an undead (a WoW model ) but when i use that model the undead only walks how can I make him run
2:So i managed to crate an Item that when is used crates a weapon which is held at the unit's hand but when i use it with units which are with wow models the wapon stais
at the at the shoulders how can I change its position and make it stay at the hand of the unit
3:That one is like the first and so here it is at some models mainly at WoW models there is a Swim animation how can I make the unit swim and show the unit swimming
I know that I should make the unit amfibia like murlocs to be able to swim but the unit only walk over water
PLS guys help
BTW sorry for the bad English