I hope you appreciate the fact that there are still some disagreements on FR and that a clash of opinions can help us both to understand different perspectives, if not perhaps modify our own.
For example, next time you roll this argument out, you can refine your list of "violent ends of empire."
British empire, Spanish Empire, French Empire, Japanese Empire, Soviet Empire all died a violent death.
British Empire - 1997, Peaceful handover of Hong Kong, for example.
Imperial Japan - TRUE! Violent end, indeed!
Soviet Empire - Ended with a relatively resounding whimper.
I think you are correct that America is a unique new "non-Empire" but it certainly does have elements of the old empire that we should learn from, avoid (corrupt financial influence/aid)...but also some things that were good (stabilizing navy, rule of law), at least, left the world a bit better than it was before or otherwise.
This is where we disagree, but that doesn't mean we're both wrong.
Nowhere in its former colonies ... has the British Empire managed to leave behind a good/respectable opinion of itself.
Simply not true. Perhaps it's true for you/India, but it is NOT universally true. Again, I lived in HK for a while, and you can't imagine a more desperately evil influence of opiates/imperial domination, right? Awful stuff. Yet, people from Guangdong don't hate the British. I don't know how many times people would tell me that they were proud of HK and were thankful for the British, otherwise HK would still be a sleepy little fishing community instead of a world financial/trade center.
I suppose you could tell them they were wrong.