First, flying on credit isn't nearly as easy as you make it out to be. Yes, a bunch of companies are buy now, pay later. They fall into two groups. The first does it based on your credit. The second is a layaway plan - by the time you get on the plane you've managed to pay in full. Ex-cons struggling to get a job usually have neither. Nobody wants to give money to a person who looks like they are trying to disappear. (Because you just know your money is going to disappear with them...)
Second, a lot of your plans require going to countries where you need another language. That's going to be a challenge for most ex-cons.
Third, while the French Foreign Legion is romantic and all, they won't take you if they find you have a criminal record. Other foreign legions are similar. They might not find out, but do you want to spend your life savings betting on that?
Fourth, marrying someone from another country is an uphill battle for someone who lacks a job. Particularly when most of the women from those countries looking to marry an American would like to wind up in the USA rather than the reverse.
These are all amazing plans, and I'm sure that some succeed with each. But they're going to work out poorly for most ex-cons who try them.
My statement is direct towards goal oriented people who want to succeed and are willing to iteratively test their options until something works. Not failures who are unwilling to take a risk or work for a reward. If you can't get a credit card, then hitchhike and/or volunteer on a yacht or just be homeless and work day labor that doesn't check your record until you've saved up a chunk.
An individual who is capable of success is capable of tirelessly executing options until they find one that works. And that is possible. Staying in the US means you will never fully regain your civil rights if convicted of a federal crime. Leaving means you have the chance of having the full civil rights of a citizen, somewhere.
Regarding going out of country, I have joined a foreign militia prior that had some ex-cons in it, that did not require anything other than a plane ticket to join. I did not know the language, but learned (some of it) along the way. Travelling extensively you learn to communicate without knowing much of the language. I believe I paid for that ticket with a credit card.
So out of my "Several Options" I can personally say (4) would work and been tested by me. Domestically I can say hitch-hiking to an oil field and sleeping in a ditch until you can afford better would work (met lots of felons that did same). I also married a filipina while I was completely broke, so (7) would work as well although I haven't personally done it, it would be trivial for me to execute it.
Sure, I had to have a skill to begin with, but saying you can't do it is wrong. Just most people won't do it because they think they can't do it.
This is not true unless you are wanted by interpol or a very serious record such as murder.
For an American, might crossing into Canada be an easier option?
And if someone was desperate enough to try to hide a US criminal record, Canada is the last country they should try, because Canada and the US share their criminal history databases.
1: https://www.canada.ca/en/immigration-refugees-citizenship/se...
The page is pretty plain language reading which makes it appear very trustworthy.
However, they avoid explicitly saying that past crimes - whether convicted and served or not - don't matter. The DO say that catching the eye of Interpol is bad.
My income quote comes from a gas station in a backwater town in the deep woods of Alabama, and I'm not a great guitarist or something amazing worth throwing money at.