Actually gladiator is ok at DD or tanking right now. My LS uses MRD and PUG to tank in the R45 raid.

No, both of us said jobs are tied to a class. This means you can use the weapons that class does.

gladiator - paladin
pugilist - monk
archer - bard
lancer - dragon knight
con/thm - whm/blm

not sure on marauder