Don't stress it. Physics is my life study, I'm used to people having something FAR worse to say other than, "Something about this isnt' right." Besides, conversation and comparison of physics is something I enjoy.
I didn't say photons can't alter direction, I gave an example of basic light mechanics, to show the way light normally behaves. In fact, light USUALLY is altered in direction due to external sources. Like the flashlight. But really, it prefers straigh line movement, unless it's in a huge relativistic event, (i.e. a Black Hole) However, quantum mechanics doesn't exactly mean photon as in light. A photon, or in this cause, the photon of every shape and size, is just a particle unit of electromagnetic representation. Since a photon is the representative particle of the fundamental force of electromagnetivity. Where a gluon is strong energy, vector boson is weak energy, and graviton (allegedly, since it hasn't truly been proven) is gravity. However, photon are attracted and repelled by it's brothers too, and most people will confuse particles of other sorts for photons. But in truth, photons can only exist as photons. But in "refraction" light doesn't slow down. Photons being a basic basic basic particle, yield an extremely low energy. So if you were to flash a flashlight on the wall, there's a good chance 99.99999% of those particles will just be absorbed into the atomic structure of the wall until the wall eventually releases the energy slowly, and outside of wave function. (Hence, that's why the wall doesn't actually light up since it can't send photons in heavy waves in any given direction. And that's why walls get hot as a lot of light is shone on them, because light feeds the energy in atoms, atoms vibrate more, more vibration makes atoms hot.)
And photons don't literally slow down, they run into barriers. Though some have hypothesized that photons literally can lose their own electromagnetic energy. As for photons slowing down, or even bending though flat out without some large outside source? They can't really, since light is dependent on total outside source interactment since light prefers wave movement.
However, Wave particle duality is a little different from what you've represented there. It just states how particles, mainly photons, can be massless, yet cause and be part of physical reactions. Eistein himself had this great experiment, where he took several different types of metal, and shined a light on them. The massless light literally knocked electrons out of sync with the atom, and caused an electric current as the electron tried to return to it's normal place. There's been others, but too many to just go through. But you are right that it deals a good deal with the actual wave action of particles themselves. Though I am aware of the wave particle duality experiments that deal with gravity directly affecting particles.
As for that black hole figure eight thing, you DEFINITELY need to PM me about that.