Z-nut coupler and other questions

Hello,

I just bought a new Robo from their website. It arrived this week, my wife won't let me use it until Christmas but she let open it for a peek. It's much easier to understand a lot of mods now that I have seen in it real life. I have a few questions.

1. The Z-nut coupler thing. I noticed when twisting the threaded rods by hand that the auto-level switch that sits on top of the z-nut swings back and forth. One side is worse than the other. I can see how this backlash would be a problem, after searching in the forums I read how some people use scotch tape and spacers. Is this the best option right now? Is there a popular mod or printable part that would address this?
2. Packaging. The Robo comes with two large foam pieces inserted from each side to fill the cavity. The foam has horizontal sections cut out for the x-axis rods and extruder assembly so the two foam blocks can be pushed together. However, the ceiling of the cutout is below the level of the x-axis belts, so the belts are kind of stretched and forced to go into the cutout section. I guess i'm wondering if this pressure during shipping will stretch the belts and simply tightening is good enough to fix or should I worry that they were damaged. Not a huge deal, just thought it was a little odd.
3. Vertical rods. As I looked up at the top of the smooth rods, I saw a piece of plastic attached to the top of the rod, and round piece of plastic from the top of the case containing the top of the rod. I was able to jiggle the rods a little bit but not a ton. I was wondering if that was by design or was that originally one piece of plastic meant to secure it firmly to the top and it broke during shipping? The left rod I was actually able to push it left at the top and it didn't stay in the plastic holder thing and it sort of tilted the whole bed. It was real quick and I didn't push it again and was running out of time before I had to box it back up. I'll inspect again this week, but I should probably print one of the z-rod stabilizers and secure it? I would think you want that rod as solid as possible and not to be able to jiggle it.
4. Must-have mods that still apply to R1? I will be fine tuning the first week or two. Was wondering what you think are must-have. After reading the forums for the last couple weeks, I would think of this:
   * Z-rod stabilizer (probably the ones by ziggy)
   * bed-level (tesseract's ?) I know there's auto-level, but still seems best to have the bed perfectly level
   * spool holder (can't remember where) seems like the spool should be mounted on top of the robo
   *.... anything else

Apologize for the long post. Would appreciate any suggestions. Thanks!
Ivin