After 3 years of bumper gap I decided to replace the bumper, mainly because the bumper tabs were in no shaped to ever work properly again. I also decided that there was a good bit of "droop" with the lower attachment of the plastic shelf underneath. Seeing the "threaded rod" fix made me think that I could take out a good bit of horizontal play and pull the bumper back up...at least cheat it upward a bit to help keep it from pulling down and putting excess weight on the upper tabs. I was able to pull up at least 1/2" to 3/4" of play. The TRD front lip added weight too, so I think it worked out for the best.
Wanted new headlights anyway, and since new headlights meant removing the bumper it seemed like a good time to do it all. The new lights fit perfectly and work well after having an adapter made for the new wiring. Made the threaded rod hangers but attached them in a different spot than the ones on this thread. Where I attached them didn't require drilling into the plastic shelf and there was a natural hole already there. 1/4 inch stainless steel rod is plenty sturdy and won't rust, along with the stainless washers and lock nuts. Hardest part was drilling into the crash bar, I think I ruined several (cheap) drill bits in the process.
New bumper along with new side attachment pieces made for a very secure fit, everything went into place and did not move again. Thanks for all the tips and suggestions that I picked up in this admittedly old thread, but I think it's good to have lots of ideas in one place for others who will certainly run into the same problems.