Poser has all these fine tools, and as end users we all have to know what each tool does.
When bending?
What does the weightmap do? What does the bulge map do? What are the magnets doing?
And, yes, what do the affected actors do? Where are they? What or who controls them?

And what is the cure? 

Crotch area: I have never had an issue here with a properly grouped object file. => There are weightmaps and bulge maps.

Breast area :  Yes, this is a trouble area due to the magnets and the dependencies.

Collar-arm :  Here we have all 4 . => Weightmap, bulge map, and magnets, and dependencies

Keep working at it, never give up hope, learn every hr, and go one by one.
Good luck with your project.

Poser 1, 2, 3, 4, 5, 7, P8 and PPro2010, P9 and PP2012, P10 and PP2014 Game Dev
"Do not drive faster then your angel can fly"!