- Your business affiliations idea would be great, but people like Trump (and basically anyone rich and motivated to hide information) have so may strategies to employ to create multiple layers of opaque barriers that it would be nigh impossible to do this with provable accuracy. And besides, as we are seeing right now, "the people" can't be bothered with such concerns. Just let a guy be rich and do what he wants, right?
- Your wall building idea is good though! Mix up some self driving AI with manufacturing robots that 3d print blocks out of whatever local resource they can grind and collect, follow some GPS waypoints, and you've got an anti-alien wall builder! You almost certainly could get that company funded, and you probably would secure some contracts. And if we're all lucky, your tech would get used by more mundane (and useful) projects like building low cost housing for poor people in desolate lands.
- I forget where I read this recently, but I read a good expose about the people who profit from the global refugee crises. So if you just want money, then I'm sure there are opportunities to commercialize and scale the relocation of refugees. Maybe you could approach it like the doctors/lawyers who created the boom in scooters (or Rascals, if you're a SouthPark fan). They figured out how to work the disability or medicare system, and some of them operated legally while making a ton of money. Or take the US auto makers as example back when they pushed the business deduction loophole which essentially started the large SUV business. Suddenly you wanted your vehicle to be heavier than necessary so you could meet the loophole requirements for gross vehicle weight.
Now what I would do is try to combine fear, exclusivity, and disaster preparation into a product that would be attractive to rich people. I mean, they already have financial assets distributed offshore and in ways that provide relative security during volatile times, but their personal physical safety is still always a concern (unless they choose to live in a bunker.) I understand that they are flocking to New Zealand as a haven - it's far away from all the dangerous poor people, and it's just a beautiful place that is generally for sale. So maybe create an emergency evacuation insurance business. They pay a small monthly fee (say 10k), and when the local shit hits the fan you whisk them away to a nice safe place. It's probably best to actually work out the details of how this could be accomplished, but on the other hand you could just roll like big businesses and just apologize and take a small financial judgement when you fail to deliver on your promises.