Should the gov be allowed to remove medical treatment from a child against parents wishes? Socialised Medicine...death panels?

Only if the medical treaters have brought suit against the parents for non-payment. 

Death panels my a$$. EVERYWHERE in the developed world has some form of socialised medicine - EXCEPT the US. Were in not for socialised medicine in Australia, I'd probably be dead by now.  If not, I'd certainly still be hobbling on a stick, addicted to opioid painkillers and unable to work, rather than running, drug-free and earning a living.
Stephen Hawking credited his long life to Britain's NHS. Thirty years ago he was quoted as saying "Were it not for the National Health Service, I would certainly be dead."

The article you linked says they're only seeking palliative care.

"Mr Thomas Evans does not seek treatment. He seeks palliative care in line with his Catholic faith principles," says his barrister Paul Diamond...

I feel a bit different about that than I would about treatment to stay alive or improve health. Unfortunately, the child is going to die regardless. They're basically fighting for the right to move a dying child from one location to another, so he can die there instead. As far as I can tell, Catholic palliative care is no different than most approaches. The goal is to keep the patient as comfortable as possible and they don't believe in ending the patient's life. I believe that's what's happening now with the child anyway, so moving him, so he can get the same care elsewhere, seems cruel to me. It's an added step- just more hardship for the little guy. I might also feel different if this was to move a dying patient back home, so they could pass in familiar surroundings. It's not. It's one hospital to another. Is the other hospital saying they'll keep the child on breathing equipment or something?

In any case, "Should the gov be allowed to remove medical treatment from a child against parents wishes?" ...
In a way, the court did make a ruling here, but they deferred to the hospital's decision, so we can call it a government decision. That said, I'm typically for a hands-off approach from the government. I think it's none of their business what happens between my doctor and me or my child's doctor and me, and I think my family and I should have the right to choose medical care providers. Barring pure negligence or child endangerment, governments should stay out. I disagree with what the parents are doing, but I don't see it being anyone's business but theirs.