There is little point in asking me questions. I'm still trying to work out what all this means and if and how it makes any difference. You could at least recognise that I do keep trying.
Well, sometimes you tell me off for posting my understanding of how state finance works, but thanks for this today. 
The difference for me is if one understands that state spending comes before taxation, and that state spending contributes to economic activity and growth, it enables one to make better judgements about spending proposals in party manifestos. Instead of working from 'can the country afford it?' one can work from 'how is this proposal going to benefit the country in terms of economic activity and growth', and, dare I say it, from judging whether proposals are going to promote a more equable distribution of the country's wealth and people's wellbeing.
Allied to this understanding of how state finance 'works', one has to understand that a country with its own sovereign currency can never run out of money because it is the state that creates and issues the currency. At a practical level it has to do this else, with population growth over the years, and with people's tendency to save when they have surplus money, or to spend money abroad, the supply of money available for the continuation of economic activity would diminish and individuals would just get a smaller and smaller share of it.
'Money' is just a unit of exchange which is trusted by the population using it. I'm sure most people are familiar with the story of prisoners of war using cigarettes as 'currency' in prison camps. We know of cultures which have counted wealth in cattle, or shells, which worked as a unit of exchange because they were universally accepted as such in that culture.
Even in the days when our currency was backed by gold or silver there would be more 'money' circulating in the form of Bills of Exchange or promissory notes (bank notes are just promissory notes) than there was actual gold or silver to back them. So long as people trusted and had confidence in the 'value' of those bills and notes they circulated and enabled economic activity. If everyone had lost trust in them and demanded their value in gold and silver there would not have been enough to go round and the currency system would have collapsed.
Since the world came off the Gold Standard in the early 1970s there has been nothing backing the 'value' of a country's currency except trust. So long as a country is politically stable, with a thriving economy and no excessive foreign debt it is able to issue as much money as it needs to promote economic activity.
Which brings me back to money creation by the state. So long as its money is trusted, resources are available to spend it on, it doesn't have excessive foreign debt, and it controls inflation by destroying excess money (taxing it away) it can issue as much as it needs. For those who mutter about 'printing money' and Wiemar, Zimbabwe, Venezuela I can post many economists' analyses of why hyperinflation occurred in those countries because of circumstances peculiar to them. 'Money printing' is not an invariable cause of hyperinflation.
I entirely agree that 'borrowing' for investment is a reasonable strategy, though some heterodox economists would argue that even that isn't necessary, the state could just create the money needed. But the bonds and savings schemes which the state offers and which are termed 'borrowing' are also regarded as a very safe way to save money, and earn some interest on savings, because the state will not go bankrupt. It will always pay, because it can.
OTOH, financial markets are the stamping ground of speculators out to make their money earn more money, which makes state 'borrowing' more vulnerable to market choices...
Premium Bonds are government 'debt', but when I suggested on a PB thread that the government might 'repay' that debt arbitrarily no-one actually wanted to be 'repaid'... 
Economics is a complex area and, it appears, not a particularly scientific discipline for the most part. I have been reading and reading round it for the past few years and have chosen to follow what I judge to be the most logical and empirical evidence based ideas.