Vocabulary,harbour

Sounds fine to me. You should decide whether you want the British spelling in the title, or the American as in the text.

Perfectly acceptable . . . and i agree with Roger, you should adopt either British spelling (harbour) or American spelling (harbor), and you should use whatever style you choose for all of your spelling.

Sound fine to me too. I'd put a comma after "easily".

I would leave out the word 'people', and put a comma after 'easily'.

I am not a person who forgives easily, but a person who harbours enmity.