Creo Parametric Mechanism and PDMlink Windchill cooperation

Hello,
I would like to ask how to properly work in Creo parametrics 7.0.8.0 connected with PDMlink Windchill 12.0.2.12 .

We work like that main assembly is composed from subassemblies. Subassemblies are composed only from manufactured parts, purchased "parts and assemblies". Purchased "assemblies" (let's say pneumatic cylinders) we use only because of mechanism.

We have library of pneumatic cylinders in PDMlink Windchill. The moving part of pneumatic cylinder is set as slider with enabled regeneration value. When we use pneumatic cylinder in subassembly we set it as flexible with selection of the dimension. In PDMlink Windchill the state of the cylinder is set to released. To prevent users to change it.

When subassembly is checked in, there is a possibility to Drag pneumatic cylinder with connected parts. When the move is performed we get yellow triangle with following messages. "Not checked out by you" and "Modified in session".

If I regenerate that subassembly, it changes to original state, but the change is still done. And in View Changes is still visible Modified Placement.

When I want to drag anything, do I always need to have check out subassembly?
Or is there any possibility to set something in config file to prevent movements as changes?
Do we use this SWs not intended way?
Why am I able to drag anything checked in, when it is basically bad?
Why there is change after regeneration?
How to easily demonstrate movements?

Thank you