Many Structural elements will move with Grids if Grids are present when placing such items and this is reflected in the Options Bar - Moves with Grids
Beams are connected to Columns so will act the same also. This is the same case for Floors and Walls which are associated to Levels and one of the main features Revit that elements are adjusted why such changes are made to references.

You can also use the Align Tool and Lock items to references such as Grids and Levels but can cause more issues later on in the model.
Rebar is Hosted inside such elements as Column, Walls and Floor so will automatically adjust if the boundaries are changed.
As regards Stairs they won't automatically adjust but give warnings where they no longer satisfy the constraints when levels change so you need to manually adjust these.
And as you have done you can PIN items to present moving and turn off the Selected Pinned Elements so this means they cannot be accidentally moved or selected


Jay Colcombe
Autodesk Certified Instructor
Revit Architecture & Structure Certified Professional
AutoCAD Certified Professional
B.Sc. Hons Civil & Structural Engineering
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