Some time after early docs were done the customer wanted to decrease the loan amount applied for. Since this will not increase his settlement costs is there a need to do anything? I realize we may provide a new GFE but as long as using the original won't lead to any tolerance violations, is it necessary?

No. The only time you HAVE to redisclose is for a rate lock. Check your TIL though. You may have to redisclose that one.