You seem to presume that beings other than men will adminster the government. That seems unlikely.
Rom 5:20 Moreover the law entered, that the offence might abound.
More law = more sin
Who makes up the government?
More? No. "More regulation," IMHO, would just lead to such a state of complexity that the average citizen couldn't know whether or not he broke the law.
Somewhere along the lines, evangelical Christianity started poo-pooing the law. I have my suspicions that a particular systematic theology, of which I am a former adherent, is at least partially responsible, but ultimately, that's irrelevant. The passages that we are not under law, but under grace have been over-emphasized, so that we've lost sight of how beautifully simple the law is; and that, to a certain extent, we are obliged to obey the moral code of the OT. (Hence, in Romans 13:9, the 10 Commandments and Lev 19:18 are cited authoritatively as binding upon Christians.)
So what's the beauty of the OT law? That it was written down in clear language, laying out exactly what God expected of Israelites. The language is not the language of lawyers, but rather colloqial. Many of the laws are either straightforward "Thou shalt not...." or equally simple (albiet more easily broadly applied) "if a man...."
What I'm saying here, therefore, is that "more laws" isn't an answer, because it just leads to complexity, and complexity doesn't help keep totally depraved men from expressing that depravity. Rather, "more laws" provides more opportunities for both intentional and inadvertant violations.
Similarly, I believe the government has a right to demand whatever taxes it needs. At the same time, as a conservative, I realize that the Laffer curve demonstrates that lower taxes encourage greater prosperity. So, while I chafe at paying Social Security, knowing I will never see it -- as a college student who earns under $5k a year, those are all the taxes I pay, really -- as a Christian, I acknowledge that the government has every right to demand that of me.
Now, as I interpret Romans 13, I see no room for a Locke-style social contract -- the authorities that be are ordained of God, whether or not they are oppressive. Nero was a legitimate governmental authority, and insofar as his commands were moral, Christians were obliged to obey him. Were Adolf Hitler my authority, if he lawfully commanded me to drive 55 MPH, I would be obliged to obey. I believe moral authority does not derive from the morality of the governmental leader.
Of course, that raises the issue of civil disobedience -- when is it permissible for Christians to disobey the state? The only times in Scripture we have civil disobedience portrayed is when the authorities commanded something that they were not entitled to -- Darius told Daniel that he could only pray to Darius, and the Apostles were commanded by the Sanhedrein not to preach the gospel. Those, as far as I know, are the only cases of civil disobedience in the Bible. I know that my perspective is contrary to the Locke social contract theory that is the very basis of American government, but its what I see.
OP: I don't know for sure, but it seems as though I might be leaning towards a theonomist understanding of government, although not their eschatology. I'd value your input; Romans 13 is a passage I've been studying lately.