I can't comment on the hospital point, other than to say that we've also needed a lot of medical care the past few years, and none of that has been my experience. Yet we live in an area with a large immigrant population in the city nearest to the county hospital. That's the problem with anecdote versus data, I suppose - each bases our view on our own experience. And another experience of mine is having European friends pay to return to their nations of origin for medical care, because their experience of the modern NHS is its being substandard compared to their own. We've been ranked 30th in the world recently, in terms of quality of care, down from 14th 3 years ago. And I doubt it's likely to improve any time soon, given current levels of funding.
Having also worked in a volunteer capacity, I have always been impressed at how tax credit / benefit savvy these people often are.
I've worked in a free advice clinic, and I hear you; some absolutely are. I've also met some who literally arrive in the country (one was pregnant and gave birth inside two weeks of arrival, and openly said that she'd been told by her friend that benefits were generous - she was horrified to learn her entitlement was zip and nada!) and seem amazed to hear that they aren't entitled to any benefit support, and yes, the NHS billing them for their planned maternity care is correct. But I met a lot more UK citizens with that attitude - and sometimes from people who were so chaotic otherwise, they would never have been capable of holding down any sort of job: their whole focus of income was the state, in perpetuity. I won't go into that further because you and I both know that it's way, way more complex than people on either side of that argument will accept.
Yes they mainly work, and pay taxes, but it is more often than not in lower paid jobs, and weigh that up against the public services that have to be provided in return. Something has to give somewhere...
Well, there's two points here. One is that you won't see the highly paid workers at a free advice clinic. It doesn't attract them as they can afford paid assistance. So you are often dealing with people who want support over benefits, and as they have the nouse to seek support, they will often be aware of their entitlements, because it's self-selecting as a client base. We don't know what those who never approach such services are like.
And then the other thing: we have almost full employment, at around 4% when 3% is deemed to be ideal. (in case anyone isn't aware: in economic terms, 0% unemployment is actually not great, because it means the economy has no worker flexibility - people can't fill new roles without leaving their old ones unfilled - and very little room for growth - if new businesses can't find workers, that brakes them really effectively. It's good for increasing wage levels, but not for the economy in general as those increases fuel huge inflation. If you have near to full employment, therefore, you need immigration to feed that growing economy. Losing migrant labour could be a disaster for us.)
That's the problem when you look at workers purely in terms of taxation paid, versus public services provided: their labour has intrinsic value to the overall economy. Extending that argument, people's contribution can't be restricted solely to their own tax bill, because they support the business that employs them via their labour, and thus the tax paid by both their employers and higher-paid staff where they work relies on what they can contribute, too - so everyone working has some economic value on that score. And that's without also factoring in the fuel they provide for the economy as consumers, as well - every time they eat a meal, buy some clothes, take a journey, they are fuelling the economy and contributing more to tax take. It's a lot more complex than saying you can assess economic contribution via one person's PAYE slip.
If the minimum wage is set at a level that is so low people need benefit supplementation in order to survive, that's a structural problem, and it affects anyone working. It doesn't actually matter where a worker comes from - someone is needed to fill that role, and they will need the benefit top-ups and public service provision, whatever. In fact I'd go further: in economic terms, there's a cost to the nation of raising a newborn to adult status. If we have immigrants, we've not paid for all those vaccinations, and early years medical care, let alone tax credits and housing benefit (mostly paid to working families, these days, due to housing costs) and child benefit and education costs. They arrive as adults, ready to join the workforce and fill a labour/skills gap, and we've paid sod all to get them there - some other country has. One of the problems with Brexit is that we're losing a load of young, working age people, while entirely possibly having to repatriate a lot of elderly retired folk who planned to live out their days in warmer EU climes, helpfully the responsibility of the local healthcare system. Because end of life care is not cheap, and when the Costa pensioners return, that's going to be on us.
I'm not uncritical of the EU, incidentally. It's a very flawed organisation. But that too is for another debate, I think! They're all such huge subjects, aren't they. So many angles to consider.