Sear and Indirect cooking questions

First off I bought a 22.5 Weber OTG with a cast iron grate for searing. This isn't the Weber searing grate that has the wire grate with the cast iron in the middle. This is an actual 22.5" cast iron grate. From everywhere I've read on here people either sear and then slide to a cooler part of the grate or do a reverse sear. MY question is with the cast iron grate wont it basically be the same temperature throughout the entire grate? Sorry I'm completely a newbie and need some suggestions on it. Also with indirect cooking what are the advantages? Do you cook indirect all the way through the cook? To me you are just trying to achieve a lower and slower cook, so why not just make a smaller fire?

So for my steaks I can use the charcoal holders on the outer edges and sear on that side then move to the middle as normal? And I think I understand what you're saying as far as the indirect cooking goes. You're basically "baking" whatever you are cooking on your pit? LMFAO dude that picture is something else!

Carbon thanks so much! That's the exact grate that I bought. I was worried about the CI grate having too much heat on the indirect side.

Chris meant to post here, but accidently posted on the wrong thread. I said the microwave and crock pot was getting old. A man can only eat too many TV dinners lol. Lol Saiko I like to cook ribeyes at least 3 times a week, so I'm sure mine wont look like new for long. Thanks for all of the inputs guys.