Bench Focusing

One I notice is that I'm always asked if I know who to bench focus when I work a show not on campus. I know what nobs to move in order to change the bench focus but I'm not 100 percent sure what am doing. When Bench Focusing are you changing to get the beam angle to be in the center of the field angle? Also whats a good example what would make someone want the beam angle not to be in the center of the light?

Blocks and Soft Blocks

I have a question when it comes to using Blocks and soft Blocks on a lighting board. From my understanding you should always what your blackout cues to have a block on them, So when you make a changes to a cue before the blackout it wont carry on to the cues after the blackout. From my understanding you want to do this when there's a big transition to another look ( different world).. I've notice whenever I add a cue before the block cue it creates a soft block and I was wondering why, because every time I delete that soft block it changes the cues I create after. I've also notice whenever I update  cue only a soft block is created. I'm guessing its created to keep the change that I have made from tracking forward? If this is the case then I understand, because what I am doing is deleting the soft blocks just because I notice Stacy doing this for Rose Tattoo.