What's the difference between 1. and 3. ?
Phrasing it differently, after such change in the target system, the table must be adjusted. I have observed many times that this is done automatically at import, but I have also seen cases where I had to manually trigger the adjustment via SE14 or SE11/tools/DB utility after the import. I don't know the clear rule, might have to do with table sizes or DB statistics.
So after the import, check in SE11, if the table is "partially active", then trigger the adjustment as described.
Thomas