I prefer to blow my nose in the bathroom.
I think that's a good idea; it gives you privacy.
Yes, because it seem hygienic.
It seems hygienic but it also gives off a good impression of you because you would look more polite. I find some people to be so nasty when they blow their noses. If you do it in the bathroom no one will get offended too.
I think it looks cool and I like to spend a while looking at my own blood before flushing it.
It is good that you are doing that discreetly in the bathroom. However, it is gross to be so interested in your body fluids, and blowing blood from your nose is concerning, so you might want to speak to your doctor about that.