The new policy now is not to man the borders, but to have patrols stopping people on all the roads further in, up to 30km in- and you will be charged and penalised with a fine on top, if you have not declared. Saying the border guard waved you through or the border was not manned, is not excuse as far as they are concerned.
This, exactly. If you have goods to declare, eg over 300CHF per person, or more meat than 1 kg per person, etc- even if the border guard waves you through, you are supposed to stop and declare- or stop by the side (there is always a car park) and declare- even if there is no-one at the border post, and you have goods to declare, you are supposed to stop and do a written declaration (there is a place with forms on the main building- clearly marked for that purpose.
About "So they ship the item with the green form"
For Amazon.de and some other suppliers you just ask the Customs to stamp the invoice and then send the stamped invoice to them for a refund.
Yep, no "green form" needed; you just need an invoice made out to you at your address in Switzerland, with the price (and MWST) clearly shown.