As an elderly person who lived through WW2 and it’s aftermath I must comment on your post. We should not be ashamed of our heritage, as you say, but I think we should learn from it. “Most British people are innocent of past atrocities,” you state. Quite right. Isn’t that just what the Germans and particularly the post war generation think. Although many of them recognise now that the Nazi regime was evil.
At one time in my service in the RAF, I served with two people who survived Changi POW camp. The Japanese have never, to my knowledge, accepted the atrocities they inflicted during that time. I do sometimes watch bits on TV that I may find offensive, unlike yourself, as perhaps it may, even at my advanced age, give me food for thought.