If I sound like I am being argumentative, I apologize as that is not what I intend. But if you look at all the smaller AIO reef tanks such as Biocubes, Nanocubes, and Aquapods, that is essentially what you just described. A filter mesh screen, bioballs, and no skimmers. Only difference is no HOB filter. I've seen some nice tanks using just the equipment provided and with the bioballs taken out.
While I do agree with the fact that an HOB filter isn't conducive to a reef tank; I think it is a little strong to say it WILL crash. You just need to do more water changes more often and have quite a bit of LR for filtration purposes. I would suggest SLOWLY taking out the filter material in your HOB and allow your LR to pick up the filtration purposes if you haven't done so already. As Sugar Magnolia said, run some chemi-pure for the polished water effect.
Well good luck man, not bad looking after 2 months!
edit: Angel*Fish, is that a Valentini puffer I see in your pic? If it is, how did it do with your coral?