In the rulebook it said:
"Objects and Magic Object are classed as Objects"

Dose it mean that whenever it said object on the instruction it meed to Magic Object also
(i.e one of the Thief special ability is that he can take one object of his choice whenever he land on a character, can he also take a magic object?)

Yep.

(why must I add this bit in order to meet the reply length requirement )