"Because money created as debt must be paid back with more money (interest) created as debt then there is no option but to steal someone else’s money or inflate your own."
Here's a non economist, layman's take on this.
Interesting use of the word "more" there which shows your being uneccessaily melodramatic. The money created as debt and interest paid are on different sides of the balance sheet, so the word "more" doesn't really apply. So yes the cost is the interest paid, the benefit is monetary liquidity. So the interest paid is akin to the cost of buying oil and paying over the odds for servicing the engine which you have to do because you allowed it to run dry.
The money created as debt is lubricating the engine, so that's a good thing right. Whilst I'm no economist I do understand a nations finances, unlike a companies finances are like a balance sheet, but where - amongst other things - there is a factor, growth, that it gets fed in from a special account where the feeding tube is invisible and that we are only ever getting a best guess as to how much has been fed in (good of course but not good if you like the certainty of double entry bookkeeping)
The interesting bit with macro economics, it seems to me is that this opaque feeding tube (powered by they way by private enterprise and the workforce in private enterprise), means there is a feedback loop. If growth slows, it can choke off the working economy. Sometimes borrowing can be used to keep the economy moving so it doesn't lose momentum. All the political debate really pivots around this and how to "use" this knowledge. Do it well and there's the potential for a kind of slingshot effect (though that imagery is actually far too strong).
It seems to me centre right economists say ok there 's this feeding tube and were never sure how much has come in, but we know it's a specific amount and we have to be respectful of the balance sheet. Whereas leftist economists tend to say, borrow, puff up the economy, it keeps things moving so the real engine of the economy keeps moving without stall. Have confidence the growth will continue. Behave too much like accountants (knowing the cost of everything and the value of nothing) and you will kill the economy. And actually most economists, left leaning and right leaning, see this mechanism has a role to play.
So when you say payment of interest on QE is stealing someone else's money, is demanding all travellers in the bus pay extra because the engine needed an extra service stealing money (when we all own the bus)? Incompetence by the person in charge, yes, but is the garage stealing? We want our bus to work and the garage are doing the work so no.
You also say "or inflate your own" as a way to denigrate current liabilities that have to be paid as a cost of QE. Well if you have produced money as debt, then you aren't cheating the balance sheet. The reason for doing quantitative easing is distinct from just printing money, is precisely so that doesn't occur.
I'm a realist. I don't believe in magic money trees. Money is a token of value which ultimately has some real basis in real assets and real work capability. Print money and you are watering down the value of each unit. Problem is, there is a lag. Money as tokens of value is worth what people believe it is worth and it may take time for the belief to adjust especially if the people are unaware of the extent of the printing of money. But adjust it will. So the BoE has to keep (liquid) money supply (one component of our national assets) in proportion to a balance sheet, the total value of which we are not quite sure.
So there is natural inflation which is a consequence of the market hedging against miscalculations in the rate of growth and consequent mismatches in money supply. This is ok, as natural consequence of unavoidable uncertainty and not knowing the variation in the value of your assets (not knowing quite how diluted they are if at all) and isn't indicative of an economic malaise. However if you print money, inflation occurs unnaturally as actors in the market hedge further to protect the value of their assets, which they *know* are being watered down, but just not by how much. Put simply you have paid x to produce and sell y, but while it's sitting in the shelf, the value of you liquid assets is being eroded so you edge the price up to protect yourself. As there is more uncertainty you hedge harder and build in greater margin for error. All your suppliers are doing the same, so the cost of x is also increasing by an uncertain amount. There's a name for that. A positive feedback loop. In this context most unwelcome.
Now quantitative easing increases the money supply, and can cause inflation if the authorities get it wrong (are wrongly guessing the rate of growth). But that isn't its intention. It isn't a necessary consequence. However if you simply print money, as a realist (e.g. One who believes there is a real value to the balance sheet even if we are never quite sure exactly what that value is) then you have to believe inflation *will* be a direct result.
So actually if you are arguing for unrestrained, Corbyn style, printing of money (which I suspect you are), then you believe in magic money trees and think you can get something for nothing.