I looked at both screen grabs, and I would recommend using individual ‘Stacks’ for your elements that are moving funny. Think of ‘Stacks’ like groups, that have dynamic properties. In that the elements in the ‘Stack’ remain relative in size and position to each other. (See image) Create these elements as stacks first. I think you may not need to make too many adjustments to the smaller ‘viewports’ if you do. There’s a tutorial on ‘Stacks’ you can check out in the video tutorials.
Hope this helps,
Rich