i second Rice Boy's questions, but i will answer anyway.
a. no, anarchism is not terrorism. terrorism has the goal of shifting government policies, and the tactic of attacking people who have nothing to do with government policies as a way to pressure the government.
b. terrorism is a jargon word, used by governments against people who they are attempting to invalidate. ("they just hate our freedoms!") so the word is either meaningless (unless you accept the reasoning of the government), or a provocation (if you are attempting to start a fight).
c. yes, anarchism is terrorism. anarchists reject fitting inside the system's accepted ways of combating the system; anarchists see ways that "normal people" support the state even when they seem to be distant from it, and we want people to take responsibility for their complicity (really, to stop being complicit), to the extent possible (and sometimes beyond).
as for trusting other anarchists, there are plenty of posts here about the wide variety of thoughts called anarchist, and how they all fit (or don't) under some coherent definition of anarchy.
whether anyone is trustworthy or not on a personal level (as opposed to a theoretical one) is a question regarding any group of people, and has little to do with labels and more to do with your own self knowledge.
edited for clarity.