I have a lot of sympathy with the "too many people" argument, but some of the problems you list are those of our own making and not population related. As shown both by the latest surveys and the many TV programs about A & E services, that problem is entirely one of abuse, and that mostly by our native population who seem to regard A & E as a form of doctors surgery. Nearly all those I've seen present are not in any way emergencies.
The police are overstretched and our prisons are full due to a gross excess of laws and an equally gross excess of enforcement. For much of my life the prison population hovered around 11,000, but in the space of just 17 years (before the big immigration surge) that was catapulted to the present constant of around 88,000. I do not believe that we suddenly became 8 times worse within a single generation, or that we need 8 times as many in prison for our country to function well.
Social services have too many cases in most instances due to our nanny state which interferes far too many times where it's unnecessary. Even where they are needed, the problems are all too often those created by the culture of irresponsibility that the welfare state created.
That just leaves food and energy from your list. We now produce far more food and are more self-sufficient than ever before as a result of our advances since the near disaster of WW2 when we were hopeless at feeding ourselves, leaving us just with energy to deal with.
Fracking and nuclear power, last problem solved.
I still believe that the problems which I listed are due to overpopulation. The more people that there are living in a country, the more demand there will be on the services and infrastructure of that country,
Time wasters at A & E Departments and Doctor's surgeries have always existed and always will. There is a percentage of any population who are like this, so it follows that the bigger the population, the number of time wasters will be greater. We notice them now because the service is crumbling under the weight of numbers (population), so we use time wasters as a convenient scape-goat. It's more palatable than to confront the true issue.
Prisons. Do you know how difficult it is to get a prison sentence? Criminals are being spared custodial sentences for some very serious offences. Offences for which they would have been put into prison, out of the way, unable to harm the public when we had a smaller population. It's the percentage rule again, there will be a percentage of wrong doers in any number of people. The more people there are, the more wrong doers there are and this puts strain on the justice system and then it fails the people, like it is doing now.
Schools, the more people, the more class places needed.
Food, we were 78% self sufficient in food in 1984, in 2009 that figure had plummeted to 59% and I expect that the 2014 figure is even lower. This is a worrying trend and an exploding population erodes the figure from both ends. The more people, the greater the demand for food and housing. So what do our governments do? Build houses on farm land. How utterly stupid and short sighted is this.
You will see that I still believe that all of our problems stem from there being too many people living here. Numbers can't continue to rise without us heading for disaster, it is a mathematical certainty. It will happen.
People sometimes say that immigrants work in hospitals and care homes looking after our aging population, and do all of the other essential jobs. They do, but who pays for them? Where does the money come from? Where is the money going to come from in a few years time? You have said that imagrants tend to return to their native country. You are probably right, they have allegiances their, they also send and take money "home." This is money which is not put back into the economy in which they are working, it's money taken out of our economy. It simply can't continue. This does happen and it is a real problem. It is also a problem which is being suppressed because it is inconvenient to let the public know about it. A native of this country, one with allegiances, one with a lifetime plan to live here will put their wages back into the economy.
We need to stop imigration dead in its tracks. People will immediately counter that with, "well what about the Polish brain surgeon?" What about him / her? We have enough people here, so let us invest in training the people who already live here. It may take 15 to 20 years to fix, but we have had 16 years of unprecedented damage done to the population of the country by Labour, Conservative and a Liberal governments, with their catastrophic multicultural experimentation and social engineering.