Sorry, I have an mistake in my comment above. I meant the window size and not the screen size.
For my 1st problem I found this solution:
All nodes are anchored on the left, and for the messages I wrote, I determine the window size Vector2.x, subtract the label size Vector2.x, and put this value as label position Vector2.x .
Do you think this is a good solution?
Would this work with the diffrent window sizes on a mobile?
Currently my stretch setting is disabeled. (If I change the window size it is stretching my UI to fit in the box ( tested on a PC))