Given a travel related situation, and given a specific question about the situation, summarize the question into a title

[EX Q]: I'm in Chile for another two weeks, but I lost my tourist card (PDI). This shouldn't be much of a problem because I can get a new one at the international police office.

However, tomorrow I have a domestic flight (Santiago to Punta Arenas) and I'm not sure if I need it for that. If so, I might run into a very tight schedule.

Do I need the tourist card for domestic flights or only when I leave the country?

[EX A]: Do I need my Tourist Card in Chile for domestic flights?

[EX Q]: How soon can I return to the US from the UK on an ESTA after abandoning the K1 visa

Background

My finacee and I were going to marry in the US as she was doing a PHD there (she is American). However whilst I was over there on my K1 visa, she decided to transfer her PHD to the UK. So we didn't go ahead with a wedding there.
I returned to the UK after spending the maximum 90 days there. Now I would like to return on an ESTA for a month or so. Ideally, I want to go back right away, I know much of the decision will be made at the border, but I can explain the situation well enough and i'm not concerned with the border officer not believing me as I have the expired K1 with me. I'm just wondering if I may have missed anything obvious? And if I get denied at the border, what impact it will have on future ESTA travel.

[EX A]: How soon can I return to the US from the UK on an ESTA after abandoning the K1 visa?

[EX Q]: I am travelling to various destinations in Southeast Asia. What is the best way to go about getting cell + data service? Is there a telecom that offers cheap roaming throughout a broad region, or will I need to get a SIM card in each country I travel to (most of my destinations will be a few days at a time, the most being a week, so this would be a bit inefficient)?

[EX A]:
Cellphone service in Southeast Asia?