Summary: Can I fly into the USA on a one way ticket on ESTA, if I plan to return to Canada by foot? And does Amtrak/Greyhound share return leg with US Immigration?
I'm a visa waiver national with a valid ESTA, permanent resident in Canada. I'm flying on a one way ticket Canada -> USA (Vancouver -> LAX). 3-4 weeks later (after a flight LAX -> Seattle) I'll return to Canada by foot (at a land border checkpoint), or by Amtrak train/bus (on a one-way ticket: Seattle to Vancouver trains/buses from Aug 9th are already bookable now).
What's my chance of being admitted to USA if I don't have an exit train booked? (I'll carry with me bank/credit card statements to prove my bills in Canada, my purpose of stay can be confirmed, and I can show the LAX -> Seattle flight booking which gets me close to the border - which, of course, is domestic and not a guarantee that I'll leave).
Can I ask for a paper I-94W form (in addition to a digital I-94W) at US Immigration (which is done before departure in Vancouver), so that I could give that I-94W to the Canadian official if I leave US to Canada by foot (instead of by a train/bus)? (As I understand, the Canadian official would then pass the paper I-94W to the US officials, so they can record my timely exit from the USA.)
If I do get a paper I-94W form, and if I return by a train/bus, can I drop the paper I-94W to the Canadian official when leaving by train? Or do I give it to Amtrak staff instead? Or will Amtrak lodge an exit record with US immigration (and I can ignore the paper I-94W)?
If, (in the future) I travel on a return ticket (flight, train or bus: Amtrak/Greyhound - not a tiny shuttle company), can the US immigration official see the return leg of my trip on their system - is that commonly shared by commercial airlines, Amtrak and Greyhound? Or do I have to show the return booking? (Of course, I understand it's safer to carry the booking with me anyway.) (Update: Amtrak cancelled the cross-border buses (that were bookable with departure from August 9th). The nearest available departures Seattle->Vancouver are from September 1st.)