In general yes, but there is a place for the white lie to spare someone's feelings. When the space shuttle burnt up on re-entry a couple of years ago, the widow of one of the crew members asked a NASA person for how long the crew knew they were going to die. He truthfully told her (I think) seven minutes. If ever there was a case for a white lie, surely that is it.
Yes usually, but when telling the truth can cause pain or suffering keeping your mouth shut, but also accompanied with lots of hugs is the best policy.
Depends, lets say you want to snog a lovely lady and she has such bad breath, that you cannot snog her , then be honest and say - your breath is not great and you may just want to brush your teeth (this is honesty). However, if you were hiding some people who were hiding from people trying to kill them, then a lie would be the right thing to say if you were asked to tell them where they were hiding. Honesty is a weapon and a tool.
i beleive it is an ideal that can not always be applied. the truth makes enemies sometimes, people want to be flattered.
and sometimes you just have to keep really quiet or just take the fifth, it might get you life or the death sentence.
i think the best policy is to do all the good you can, so you'll never have to be dishonest about the truth.