I have been to a Delta sales pitch in the UK, and to be honest I found them to give a lot of "vague" promises - like there is always a chance that things will change, and you can instruct with us, but we can't promise you anything now!
"but we are the best and biggest (+one of the most expensive schools)"
But once you give your money, and you start your course, all those promises will turn to nothing. From what they said, you could during a degree, work for them for "free" - however this would have to be during a degree course I think of 4 years (Possible this fact is not 100%, my memory not 100% just now on this)
But again this was followed by BS like " but we are number one flight school in US, so we will maybe get new rules soon, (or next year)"
Now if you are young and dont have to much experience in life and business, you might believe such BS! But the truth is that they will tell you ANYTHING to seal the deal, get your business, your money!
But on the paper you sign, they will not PROMISE YOU ANYTHING with regards to work, because they legally can't employ you!
(Actually with regards to investments in the US, you don't need 1mill $, around $100.000 is enough, as long as it is not in property, and that within 12 months you will employ 1 or 2 US citizens + you spend $10.000 on a US immigration lawyer every year, not knowing 100% sure if you get a visa for your next year of business. They want to see that you can sustain yourself, and will be providing work for US citizens, should increase every year, until you at least employ 3 - 10 US citizens. Anyway that is off topic, nobody here is going to go that way anyway, furthermore such a visa would be specific for one business, you could not part time work as a flight instructor anyway.
Also from what I understand, all US FO programs, are for US citizents/green card holders ONLY!
The Delta promise you an interview, but they can NOT provide you the visa you need, unless you take a degree program. It is easy to promise you an interview, but it is you who have to make sure you qualify for the correct visa to work in the USA, not Delta Ac., so you can pass an interview, but not get the job because you do not have the correct visa, and you can not obtain this.