Samurai as a subjob is weak until 60 like lionx said. Until then there are much more viable solutions. I personally like war/mnk. For the Counter ability alone. I love being on the verge of death, with a cure 10 seconds away, and death 5 seconds closer. Then the mob swings....and gets countered...pwned. But war/mnk will never be as good as pld/war for tanking, and it's most definitely not a good damage dealer. But it'll do in a pinch. And Paladin as a sub-job is completely pointless.
Get your warrior up to 37 and never deal with it again.