Hi Jugo, thanks for your informative review plus follow up! I was thinking hard about Zelex and chose Irontech over Zelex, because, at that time, Zelex did not have motorized hips and Irontech did. I am looking for a taller body and am back thinking about Zelex.
I had your loose shoulder joints from Day 1 and, after 7 months, I had the same paint fade. I am actually happy the overly red paint on the joint areas is all but gone, only the left knee and the fire-walking red foot bottoms remain.
For the shoulder joint, with her lying flat on her back, I straightened the arm at the side position, then lifted the arm to 90 degrees in front, then I felt in her armpit for the nut and lined it up so the incision would be least noticeable. I made a small opening and scraped away some of the silicone covering the 11/16" nut and, with a socket wrench plus extension, I carefully tightened without over-tightening. I left the access hole open because it did get loose again. I believe the bolt head is spot-welded so adding brass washers is not an option and the nut is pretty much flush.
Judging by this Zelex skeleton pic you may have to position your lady face down and position her arm 90 degrees backward to put the nut in the armpit, FYI.
Thanks for the link to Averbeck70's positions list, very helpful