What is your opinion on the use of the atomic bomb? should it have been used on japan? should it have been used at all since wwii? why or why not?

Well yes the atomic bomds should have been dropped on Japan to end World War II for one reasons.
1) If the project would have been delayed then American Forces and the USSR Forces would have no choice but to invade Japan. The American Forces would have had to invade the most southern part of Japan which was actually the most defensive and had more bunker than anywhere else more than that of Normandy. Also, the main Forces in the pacific where the United States Marine Corps and they knew they didn't have enough soldiers to take the island like they have had in the early part of the war so what they had to do was then pull the Army over to invade.
So basically what I am saying is you you rather have lost a huge number of American soldiers and turn Japan in to a Place like Germany or drop the bomds

We should have used the atomic bombs a lot more than those two times

The use of atomic bombing in areas populated by civilians was unnecessary. The U.S could have bombed areas (factories etc) in Japan that would strip them of their ability to produce resources and soldiers.