Whether with the discovery of supersymmetric particles or not, I think the discoveries in particle physics will be of the utmost importance. Perhaps new data will appear that will redirect the course of research on cosmology and other fields of physics.

yes

I think in order to fully detect and understand dark matter that major advances have to be done and we may even have to achieve faster than light technology beforehand. I think one possible (but probably unlikely) reason that dark matter does not reflect light and largely escapes detection is because it travels faster then the speed of light, hence needing FTL technology first, the keys to which lay most likely within the particle and quantum physics.

Regardless of the above statement, I believe that we will be able to better detect the visible effects that dark matter has on particles as our collider detection techniques and high-energy experimentation capabilities increase.

If new particles are discovered, that could explain the missing mass (I think).

It could eg. explain missing mass in our Universe