Hi Steve,

> something like ,"import sub-part" button, after selecting
> a file, it opens a object browser, allows you to select a
> group/s , then "done"

There isn't anything all bundled up like that right now - the best way for making a part library is to make each part into a separate file, then the file open dialog becomes your name browser, you can organize things into different sub-folders to organize them too.

- Michael