As far as agnostic atheism, I can see little difference between 'I don't believe God exists, but prove me wrong if you can' and 'God may or may not exist' besides implying that one option is more likely than the other.
It's that the label "agnostic", unqualified, is general taken as meaning undecided. By contrast "atheist" implies a much firmer position, though it need not be a dogmatic one. If I in future see a reason to change my own position then I will have no problem doing so, but presently, I am reasonably confident God does not exist.
Generally, I wonder at the things some people seem to accept as fact, based on human efforts. Theories based upon theories upon theories seems to me more akin to a house of cards than a worldview. Always, Theists are reprimanded for denying the "concrete evidence" for different theories; theories that are way over our heads. But somehow, a general agreement that "it makes sense", and the blessing of some guy in a wheelchair constitutes irrefutable evidence. Human knowledge is so pitiful that, accordingly, I fail to understand this phenomenon.
The ability to predict the behaviour of physical system to the highest accuracy we can measure is what constitutes the immensely strong evidence the theories are correct.
To give an example:
In 1915 Einstein published his theory of general relativity. His work was based entirely on theory. Yet immediately, it precisely described the behaviour of Mercury's orbit, something Newtonian mechanics failed to do.
It also predicted the exact amount light from a star would be affected by gravity. The prediction differed from that of Newton's theory. In 1919, observations were taken during a solar eclipse - the stars near the sun, made visible due to the eclipse, were seen as shifted from their usual predictions. The shifts matched General Relativity. (The data from 1919 was not very good, but more recent data has been more precise).
By the 50s, it had been established the Universe was expanding, and two rival theories had arose - Big Bang and Steady State. In 1948, Gamow, Alper, and Herman made a key prediction - that the Universe should be permeated by the 'afterglow' of the Big Bang, now redshifted to wavelengths of about a millimetre, and that said afterglow would show a so-called black body spectrum.
In 1963-64, Gamow, Alpher, and Herman's work had been mostly forgotten, when Penzias and Wilson were attempting to track down a vexatious source of interference received by a radio antenna. This radiation turned out to be the Big Bang's afterglow - the Cosmic Microwave Background. Combined with other existing data (notably that the only quasars are all far away and thus billions of years ago in time) the Big Bang was proven - the Steady State, refuted.
It was also predicted that there should be variations in the CMB. Astronmers searched, and found nothing. They searched some more, and eventually, in 1991, the COBE satellite found the variations - 1 part in a hundred thousand. They also measured the spectrum, and found it to be the most perfect black body spectrum ever found in nature, in perfect agreement with theory. Draw the theoretical line on a page and the errors bars on the data are smaller than the width of the pencil line.
If you ever use a satnav, the GPS system depends on general relativity. Use Newtonian mechanics and your position will be miles wrong.
As for the other great theory of physics - quantum mechanics: the now omnipresent USB flash drives rely on quantum mechanical behaviour to store their data. As do nuclear bombs, lasers, and many other things.
Accurate description after accurate description, and fulfilled prediction after fulfilled prediction.
That is why I am confident the scientific worldview is correct.
PS: I started work on this post before the Great Sage had made the one above.
