How can I insert a carriage return into an RTF file?

I would like to use a position frame and, inside that, a vertically oriented text. But it is shown horizontally in the output.

I have RTFs which are formatted in double columns and I invoke other, identically formatted, RTFs. Now I want to change the page margins. In what RTFs do I have to perform the formatting operations so that they take effect when printed?

Is it possible to define the column width in a multi-column text?

How can I perform rounding in RTF text modules?

The file size of my RTF document grows very large as soon as I start using graphics. How can I prevent that?

In my projects, text fields keep causing problems. How can I avoid that?

What version of Word should I use and what must I take into account here?