I would like to see a source for that (the debt part) and why Britain seems to have borne it so easily.
Yes, easily. Britain shows no signs of being nearly broke or exhausted in this period, quite the contrary.
I know (source: Kennedy) that Britain spend 1.6 billion on the Napelonic wars - and "total income" covered 73.4% of that, despite the amount spent in total being two and a half times the amount spent on the other major wars between 1688 and 1783, which means the amount raised by loans was not quite twice the amount having to be rasied for the other five wars in question where as total income is three times the amount in question.
In short, Britain had an easier time funding the war outside of loans than ever before, even if the figure in question looks enormous.
http://www.ukpublicspending.co.uk/uk_national_debt_chart.html
Now yes they did make the interest payments, but the overall debt was very high. And if the interest rates spiked for any reason, the UK would not be able to repay the debt. Another source I had showed a much slower repayment from 1820 to 1840, probably reflecting differing estimates of GDP. The UK paid 1/2 to 1/3 of France interest rates is a big reason they did ok. Also the industrial revolution and about 100 years of peace did the rest. The Crimean war was not really that big or that long compared to the Napoleonic Wars or WW1.
And there is evidence of financial stress in the devaluation of the pound in about 1812. There is a reason it is the "pound sterling" or 92.5% of a pound of silver not a "pound". If the Napoleonic wars had lasted longer, then the UK would start to see a series of devaluation such as we see in France, Russia or Italy. They took the economy to the edge, without quite going over the edge. This is why I said another major war with the like of the USA or Russia would have crippled them. Just add on say the cost of fielding a 3 million to 5 million man army for 4-5 years in a "victorious" war over Russia. It would have broken the back of the British Empire, much like WW1 or WW2 would have. The UK in 1910 (35% Debt to GDP) was much stronger than the UK in 1830 (180% Debt to GDP). Or put another way, just imagine the UK had been less frugal between the Napoleonic Wars and WW1, so it entered with a debt of 100% of GDP. It would have run out of money to buy things in the USA at least a year earlier and lost the war, all other things being equal.
The key to understand the UK success is spending just enough to keep others from challenging it, but as little as possible on the RN and British Army from 1820-1890. As soon as we see the Boer War and the German Naval expansion, we see the UK have to leave splendid isolationism not out of choice, but out of necessity. It sounds nice to say we are going to have 1.6 to 2.0 times the Navy of Germany, but that alone largely eats the entire military budget. To have an continental size army would have broken the budget, not to mention cause severe internal political issues.
Part of the reason the USA golden age will not last 100 years and the UK lasted 100 years is the USA was not able to find the right balance that would keep our interest safe without spending so much on the military and wars like Vietnam, Korea, and Iraq.