LINK to discussion about rent- an- onward ticket sites.

If this had been posted/moved to Thailand branch, OP would have been told that Phillippine passport holders get a visa exemption of 30 days, renewable once for 1900baht. Currently only two visa exempt entries a year are permitted on overland crossings. Changes to tourist visas are on the way with a trial to begin sometime soon.
May (being the operative word here)need to show onward ticket, accommodation bookings and proof of funds.

You will have to provide an onward ticket out of the Philippines at check-in in Chicago. If you have checked-in luggage you will not be able to claim it in TPE. Your airline may debit your credit-card with the fare difference after you fail to board in TPE.

Agreed with above. But I did find at least one website that says you may be asked by your airline for an onward ticket when traveling to Mexico. To be sure, check with the Mexican embassy to your country. Most of us are from USA, Canada and Europe, and rules may vary by citizenship or airline.

it doesn't need to within the 30 days. Once - but only once out of many times - in London, a junior check in clerk did query the onward ticket being outside the 30 days and summoned a supervisor. All I had to do was explain to them that there is about 60 immigration offices dotted about the Philippines and I was going to get an extension at one of them.

Welcome to the forum.

I can't comment on the rules of the F1 study visa (and whether a skip to Canada is sufficient) - but in general, to enter the USA under the Visa Waiver Program (the VWP - requiring ESTA clearance) you are required to have a return or onward ticket out of the US within 90 days (air, ship, bus - car is not sufficient).

And further to that, evidence of leaving "North America" overall, which means Canada, Mexico, and the Caribbean, prior to any intent to return to the US. You don't have to have a ticket out of North America, as such - you might be going to Canada for years, and the US isn't concerned about that.

Residents of North America don't have to leave all of North America, or have evidence of intent to do so.

I don't know how those requirements of the VWP will meld with the other issues relating to the F1 visa. Presumably the F1 over-rides the VWP requirements, but probably in ways that are complex (including the fact that the VWP requirements kick in even before he steps on the first aeroplane).

He might do better on ALL counts to plan a nice week in Costa Rice between the two visas, and have air tickets to prove it. All Central American countries are not classed as part of North America.

Has anyone got experience of travelling by ferry from Penang to Langsa (Aceh), north of Belawan, which is one of the only authorised port of entry on Sumatra for the 'visa exemption'.

If you want to leave from Penang then fly to Medan , get visa exemption there if that's what you want then travel by bus to Langsa . Why do you want to go to Langsa ? are you heading to Banda Aceh ? you can take night bus from Medan to Banda Aceh if that's the case.
If you want to avoid tougher Medan immigration as Lung Paul mentioned its easier at Dumai . If you took the 2 hour boat from Melaka if you happen to be near there then at Dumai they tend not to ask too many questions and are not likely to be demanding about onward tickets. If you go that way then take a night bus from Dumai to Medan (you will have to wait hours for the bus in Dumai) then another night bus from Medan to Banda Aceh.

ATMs are the way to go.
Note that most countries require, at least in theory, an onward ticket to allow you to enter. This is most likely to be enforced when flying into Indonesia.

Panama's requirement for proof of onward travel is the same for visitors from all countries and from any destination. It's enforced by the airlines because when you are stopped by immigration, the airline will have to put you on the next available flight back to your point of embarkation. They lose two seats that way; the free seat they have to give you, and the revenue from the seat they could have sold. I understand that they also have to pay a big fine.

Most people buy a separate, fully refundable airline ticket from Panama to wherever. Then, as soon as they clear immigration and customs, they cancel the reservation. Delta and Copa also have a window (it's either 24 or 48 hours) where you can cancel a reservation without incurring any penalty. Some people have done that with less expensive, non-refundable tickets. The problem with that is if your flight to Panama is delayed or canceled, you may not be able to cancel the onward travel ticket in time. There are also online services that will provide you with an onward travel ticket. I don't know if they are reputable or not, but I'm highly skeptical.

Having done the Yorks - Paris / Brussels journey more than once with just the short walk from Kings Cross to St Pancras, one comment I would add is that it is often considerably cheaper to book separate tickets into London and then London- Paris, rather than a through ticket to Paris. The disadvntage of this is that with a through ticket, if you are delayed coming into London, your ticket should be transferable to the enxt available train from St Pancras to Paris, whereas you need to allow time for the inward journey to London to be delayed with separate tickets. As a result, some of Meckers times above you might want to review - and remember you need to be ready to go through security 30 minutes before the train departure from St Pancras.