idk about the sixline, i think that mystery might kick its but, there pretty tuff, unless you have one of those super mean sixlines. its hard to say, they may or may not, how many gallons is your tank??
the mandarin shouldnt be a problem at all i would think....
and as for jumping, rob at exotic has had one in his show tank for a long time, as well as robert and larry at eco reef, and neither have had theres jump. both show tanks have no canopy, glass or any other device to prevent jumping.