"For instance we can't align the menu in the same hight as the image and logo:"
The Margin above the menu may be set to px instead of the responsive %
Screen Shot 2022-04-03 at 8.27.52 PM.png
Or your Gridder Frame may be set to px or %
Screen Shot 2022-04-03 at 8.29.56 PM.png
This can be changed in Gridder Defaults:
Screen Shot 2022-04-03 at 8.30.12 PM.png
I feel a combination of two seperate measurements could be the issue.
"We can't add a space in de desktop view between image tiles."
Are these spaces the Titles of Project's in a Thumbnail Grid?
If so they can be set within Customizing ▸ Project Thumbnails
Project Title:
Screen Shot 2022-04-03 at 8.38.13 PM.png
Best wishes ✨ Richard