I've just learned about script variables. I see how this would solve both problems.
Question 2: How do I "get" the contents of a field from Layout1 into Layout2?
With the correct relationship linking your two tables, "field2" can be removed from your second table. Instead you can just add the related field from the first table to the second layout in order to display this data. If you do need to actually copy this data, you can set up a looked up value field option on this field so that the data is automatically copied when the ID number is entered by a set field step.