1) Is it correct to build a child without NOEXE=TRUE in form of one INstallAware "----.EXE"-File or
If you want to use Run Light Mode command, yuo must build the child installer setting NOEXE=TRUE.
Otherwise use Run Program to execute an ordinary package.
2) (?) is it necessary to use an uncompressed child-build?
If you want to use Run Light Mode command, yes, it is.
3) Is it possible to put this "Child.EXE" (1) (one File) into the supportfiles and I can run it it with the "run light mode" - command?
I suggest to use InstallAware File Bag in order to store correctly all files and subfolders of the uncompressed Child build.
4) Where can a get a script showing me the usage of "BAGfiles" in IA 15?
See note below.
Is it necassary to first get a PLUGIN?
No, just Install all IA features in order to be sure you have installed all components.
It seems, that die "uncompressed"-Child-Method (2) works, but the "child.exe" (1) do not.
As I said previously, you should use the "uncompressed"-Child-Method with RUN LIGHT MODE.
Please note, use the attached project that demostrates how to use RUN LIGHT MODE command.
The attached compressed rar already contains the builded project ready to run.
If you want to re-build the project that uses the RUN LIGHT MODE command, you must replace the FILE BAG command path I used with the one you used to store the child project. With File Bag command are not allowed script variables or relative path.