1. It will have blood they say , blood will have blood.

Blood = murder -metaphor

why would you use the word blood instead of murder?

Because its more direct and it adds more enthusiasm.

which is more effective? = blood because the word is more

This mean’s that Macbeth is trying to change something important – trying to go back in time to stop something from happening.

2) I am on blood step’d in so far that should I wade no more , returning were as tedious as go o’er.

i think he’s trying to say that he went to far and now he’s ashamed and he doesn’t want to proceed.