Firstly lots of other people have printed this file with no problems and free moving joints. I've printed quite a few myself on a Replicator 2 and 5th Generation Replicator with no problems.
I don't know what your slicing app or machine is but it sounds like it doesn't handle fine details and clearances like many others.
To make the pins bigger than the current 3mm would mean changing the look or just scaling it up which you can do anyway.
Using high Z resolution isn't the answer... this is about X / Y accuracy
Also , Luminous filament tends to be more brittle than regular PLA
If 3 or 4 shells and 75% infill doesn't make it strong enough then you have other things to deal with to get really good prints
Hope this helps.