Great topic!
I'm not in a relationship and since my relationships ended, perhaps I am not the best give advice on any of these topics. I try to be honest without being hurtful. If that makes sense. I have lied to keep the peace and I have told the truth and caused a fight. I don't like who I am when I lie so I really try to be honest without being hurtful.
Arguments - Do you apologize when you know you're not wrong?
Since you used the word arguments and not the word discussions... I will say that I try to apologize for my part in making it an argument. Was I trying to 'win' or I was not listening and only waiting for a chance to give "my side"? Was I trying to look smarter or superior in my opinion? Usually, I have a part in the discussion becoming an arguments and I will apologize for that.
Attraction - Do you deny that someone or something else caught your eye for a just moment when asked?
I have denied it in the past--guilty as charged.
But as a Femme, I am not given eye candy very often (there are not enough Butches in this world!!!) so I think I should be given a pass.
Sexual Satisfaction - Do you fake it or are you honest?
I am honest. But it is easy to say that because I haven't had a whole lot of sexual partners (I am a serial monogamist--dagnabbit) and they have all been sexually compatible with me and we could talk about sex. The last person I had sex with was really wonderful and seemed to know my body so well. We didn't end up in a relationship (maybe I am getting away from serial monogamy afterall) but I still think I could have told them if I wasn't satisfied.
Breath/Body Odor - Do you say something or live with it?
If I have just started dating someone, I probably wouldn't say anything. But if it is my partner, I'd say something because I'd assume they'd want to know.
Please, please, please, always tell me if I stink! I can fix that!!
Friends - Would you tell your partner if you didn't like one their friends or just grin and bear it?
Oh... such a hard one. I really want to say that I would be honest. But most likely I would grin and bear it for as long as possible
if it was a really good friend. Friends are so important. Maybe being so far away from most of my friends, influences this answer.
Again, I am answering these questions as a single person. I'm looking forward to reading more responses. The times I find it hardest to be honest is when I hate a shirt they are wearing and they love it. I just can't bring myself to tell them the truth.