I read some of the snoopes article on it and it sounds like the military at that time commonly paid to use commercial airplanes to transport soldiers.

I know that's not a credible source but I can't imagine Trump's campaign not mentioning this one if he had done it for free.

I would imagine that he is referring to things like gold, silver, platinum, etc. Also things like food and tools. Benefit of food and tools over gold is that they have a practical use if you were to lose your job or have any bad life event, doesn't have to be the apocalypse for them to be handy.

When you spend your money or your time on something, ask your self if it is increasing your freedom. Buying tools to maintain your life is increasing your freedom. Paying someone to maintain your life is not buying freedom. Watching sitcoms is not increasing freedom. Taking action on guides or tutorials is increasing your freedom.

I don't know about all crypto but the problem that I see with bitcoin is that if any one entity controls 51% of the blockchain then they control everything. As the chain becomes larger and larger the number of entities with the resources to run it becomes smaller.