How to place text vertically! (radially) in a circle?

A simple rotation is what you need.

Start with just the circle and "text1". Turn on [Snap to rotation centre] then use the select tool to move the rotation centre of the text to match the centre of the circle. Open the transform dialog [Object > Transform]. Go to the [Rotate] tab and enter the angle you want between text lines. [ctrl+d] duplicates the text then click [Rotate > Apply] in the transform dialog. Repeat [ctrl+d] [Rotate > Apply].

Here's the result.