AutoCAD Civil 3D

[#1]

I create the sampleline on the option "by a range of stations" so the sample lines were created on the horizontal geometry points. When I change the geometry of the alignament, the sample lines's local change or I need to do the process all over again?

[#2]

Try it and you'll see what happens.  You may have to add some, depends on how your alignment is edited.