Did I read somewhere that when doing a full boil, I should reduce the hops? All hops or just particular stage of hop addition? Also, from Mr Palmer’s book he recommends steeping speciality grains in a one gallon boil then adding the rest of the water. Can’t see the science here.
You will get slightly better utilization of hops when you have a full boil. That means you could reduce the hop amount for the 60 minute bittering hops by about 10%, or just leave it as-is. The difference isn’t enough to make much of an impact on the final taste.
The science behind the small volume used to steep grains is that the act of mixing grains and water will reduce the pH of the water, and the amount of pH reduction is dependent on both the type of grain and the ratio of grain to water. It is important that the pH is reduced enough, as high pH will leach tannins from the grain husks and make your beer taste harsh. So Palmer is being on the safe side by keeping the volume that small.