I use the mean nodes when calculating the lunar nodes. I've found them more accurate in my practice. The names mean and true are slighly misleading. For a deeper understanding of how the calculations are made, read my article on the Mean Nodes vs. the True Nodes.
I have found Placidus house cusps to work consistently the best for me. I am not rigid about it except with my students -- astrologers should celebrate diversity, I think! But I would always use Placidus, and just trust the message of the symbols from that point of view. For House positions I also allow a cuspal orb of about 1.5 degrees -- e.g., if the 9th cusp were at 20° Gemini and a node were at 18.5° Gemini, I would read it as conjunct the 9th cusp. That seems to work consistently well for me.
The one caveat would be the eternal question of the accuracy of the birth time. Even when they looks accurate - i.e., "4:56pm" you never really know. Before adjusting a recorded time of birth, I would always apply rectification techniques, though. I would never do it just to make a nodal story fit.Tthat would be a good piece of evidence, of course. But I would want corroborating evidence as well.