Creationism

[Belacqua]

(1, 2 & 5 are the exact same argument)

No, they're really not. They look the same to modern people because we're not used to the terms, maybe. But causality, essentiality, and becoming are different things. 1 and 3 are cosmological, and 5 is teleological. 

depends on the unstated assumption of "firstly, assume god exists

No, it really doesn't. All the arguments begin with some basic thing, like "contingent things are caused by other things." That doesn't assume a god at all. 

Aquinas doesn't prove god's existence with this argument

It's been repeatedly pointed out that each argument attempts to prove only what it attempts to prove. No more. So a first cause argument argues for a first cause. That this is God is something we need other arguments for.

he doesn't offer any evidence for the assumptions underpinning his arguments nor show that they are necessary conditions of existence.

As has been pointed out, none of the arguments is a stand-alone syllogism. Each one is more like the table of contents of elaborate discussions which require more knowledge. This was understood by the people who read them originally, and they were embedded in books which assumed knowledge of the various terms -- like "cause" in the Aristotelian sense. 

The idea that they can be detached from larger discussion and used as stand-alone proofs is a modern mistake. 

Argument three assumes that for anything to exist something must exist for ever.

No, it doesn't. As has been pointed out repeatedly, starting points and "forever" are not a part of the argument. It argues that for the full of chain of contingent things to exist, some non-contingent thing must exist. 

  There are two problems with this 1) it's an unevidenced assertion given with no attempt at proof and 2) if true it doesn't lead anywhere near god without a lot more evidence being provided to come to that conclusion.

Because 1) you have to know a lot more than just what's contained in the summary. IT'S NOT A SYLLOGISM. And 2) it isn't intended to prove the Christian God, it's intended to prove a first cause. I'm losing track of how many times I've typed this out. 

Given our current knowledge we have a possible candidate for an "eternally existant" thing, which is energy, not god.

The existence of energy requires that existence itself is real. Existence itself is the first cause. 

Nothing in physics contradicts this. 

Argument four is simply Aquinas assuming there is a perfect everything

No, it doesn't assume that. It assumes that in all matters where degrees are relevant, there is one thing which is the greatest degree of that quality. 

This is Aristotelian and needs to be read in that context. It does assume that a quality in an object is caused by another object with the same quality. This doesn't sound right to me, but again, it is a long involved argument, not evident from the summary in the Five Ways. 

and asserting god embodies all those perfections.  

No, not asserting that. It ONLY says that there must be a greatest degree of a quality which causes that quality in other things. As with the necessity/contingency argument, to get from there to the Christian God requires far more additional proof. 

And again he makes no effort to show that if his premise is true that it must lead to god, he simply asserts it.

Because it was never intended as a stand-alone syllogism. Each term requires further study.

Even in his own time his fellow theologians could see tbat Thomas Aquinas was arguing from faulty assumptions and often making "because I say so!" declamations.  They knew his three ways were not proof of god, nor that  they provided evidence for it.

If one thing is certain in this world, it's that the Scholastics argue about everything. 

Can you point me to one contemporary case in which it was asserted that all the assumptions are faulty? 

I'm curious where you're getting your information, since every bit of it seems to misunderstand the issues.