Very nice post and very complete! I really like it!

The way used to detect the invisible at the LHC is actually a bit more complicated. In short, in the case you have a collision only producing dark matter, from a detector standpoint it produces nothing and is thus not recorded. One indeed needs to trigger the detectors for a collision to be recorded. Two of my last three publications actually concern this topic. If interested, I could write a post about that ^^

Concerning MOND theories, we now also have hybrid dark-matter/MOND theories on the market which seem to accommodate data better.