"Primitive" snakes

i) When I read about reticulated pythons, it's amusing to see them described as "primitive" snakes. As if these are early, draft models of more advanced snakes–like venomous snakes.

Yet reticulated pythons are perfect killing machines. Quick, clean, bloodless. They have rows of incurved teeth to get a solid grip. They suffocate their prey within minutes, then swallow it whole. They have detachable jaws which enable them to swallow prey wider than themselves. They have gorgeous camouflage, ideal for an ambush predator. 

It's a very efficient, complete mechanism for killing and costuming prey. How would you improve on that?  

It doesn't look like a primitive design which natural selection has to get the kinks out of. It's not a test model, but a final design. A fully developed, fully-functional system. 

ii) Moreover, it's not transitional to venomous snakes. Death by constriction and death by envenomation are two unrelated methods of predation. Python design is not a bridge to a rattlesnake. 

iii) Darwinians counter that pythons have vestigial hind-legs. And they point to fossil snakes with hind-legs. For them, that's evidence that snakes evolved from quadrupeds. But it seems to me that there are problems with that inference:

a) Vestigial structures don't disprove special creation. Structures can atrophy through disuse. Take blind cave fish. That's not inconsistent with special creation or fiat creation.

b) Why assume a fossil snake with hind-legs evolved from quadrupeds, rather than viewing it for what it is–an extinct snake with hind-legs?

c) To my knowledge, only the largest snake species have vestigial legs (of that's what they are) or hind-legs (in the case of fossil snakes).

That raises the question of whether hind-legs were functional. Do snakes that long and heavy need hind-legs–unlike shorter, lighter snakes? Did that help them get around, or get going? 

d) By parity of argument, should we infer that walking catfish evolved from quadrupeds? Are their pectoral fins vestigial legs? 

iv) Are pit-vipers more advanced than mambas and cobras? Infrared vision might seem to be a more advanced design. But that's only beneficial for nocturnal predators. That's not advantageous for diurnal snakes like mambas and King cobras. So it' s not more "advanced." 

If, moreover, all snakes had infrared vision, then they'd be in competition night and day. By contrast, if some snakes are diurnal while others are nocturnal, that's a time-sharing arrangement. 

Retractable fans might seem to be more advanced than fixed fangs. Yet venomous snakes with fixed fangs are some of the world's deadliest. 

v) Another fascinating predator is the electric eel. In evolutionary terms, this is a "primitive" creature compared to, say, a dolphin or leopard. Yet it's a marvel of engineering efficiency. It uses electricity for offense, defense, and navigation (like radar). It stuns or electrocutes its prey, then swallows it whole.

A very compact design. How would you improve on that? How is that "primitive"?