Our reasons are so full of regard
That were you, Anthony, the son of Caesar,
you should be satisfied.

(i) What, according to the speaker, were the reasons ?

Brutus is trying to convince Antony that even if Antony would have been the son of Caesar, he would have been satisfied with the reasons for killing Caesar. The reasons were that Caesar was on the verge of becoming a tyrant and since he considered himself larger than life, he would have become a threat to Rome which was a republic. Thus, for the betterment of Rome, Caesar had to be murdered.