is their any plan to let users create their own samples in halion format and sell them as VSTi?
I have a lot of issues with Native instruments kontakt as these instruments that I created were stolen
HALion 6 allows you to create your own instrument libraries, including scripting, macro pages, etc. The libraries can be tailored to run in HALion Sonic SE3 (which will be free to use), HALion Sonic, and of course HALion. Making libraries for HALion Sonic (SE) imposes some restriction on the features (number of layers, macro pages size, …). You can of course sell the libraries you created for the HALion platform. But that would be a HALion library, not a VSTi per se. The user would need one of the above mentioned software tools to use the libraries.
And regarding copy protection, the libraries are generally distributed as VSTSound archive files. The samples in those files are - to my knowledge - protected, meaning they cannot be extracted or exported by HALion. The raw content is scrambled (encrypted) in the file (at least it was that way with HALion 5). You can even protect layers, so users cannot view or edit the details.
If you are referring to mechanisms requiring a license to use your library (as NI provides it for “Kontakt Player Libraries”), Matthias mentioned that VSTSound archives can be protected with an eLicenser license code. But that feature is ment for commercial library developers, who got a license agreement with Steinberg.
For reference, here’s the link to the topic in the German forums: Re: Schutz von eigenen Samples