Was the death of Julius Caesar justifiable?

Not at all. When he was asinated, he had been in power for five years, and none of the so-called fears about him had come to p. The only people against him were a minority of senators, 60 out of 700. Curiously, the asination came just at the time Ceasar was about to root out corruption and graft in the Senate; so probably the senators had no 'noble, honorable' ambitions (as Shakespeare portrays it), but were just out to save themselves.