Let say :

- If i've created a few presets i want to share with the standard (or even the pro version, that i don't own yet) of the basic models or any of the free addons would these user presets be able to be loaded also in the stage version ?

This of course, knowing that they will be drastically reduced parameters in the case...

Welcome to the forum Krakatau.

Answer is yes, however, Pianoteq Stage will load only the settings that are available in the Pianoteq Stage interface (copy pasted from the FAQ http://www.pianoteq.com/faq.)

- If i've created a few presets i want to share with the standard (or even the pro version, that i don't own yet) of the basic models or any of the free addons would these user presets be able to be loaded also in the stage version ?

This of course, knowing that they will be drastically reduced parameters in the case...