You could be hurting yourself by submitting so many credit card applications, which can be a red flag in many systems regardless of your personal credit score. I realize you say that according to Chase your score is over 800, but what does TransUnion or Equifax say your score is? Do you belong to any of the sites that let you track your score for free? It's a good way to see what's on your report in detail, especially when it comes to inquiries.
Some banks, such as Capital One, will deny you a card you may otherwise qualify for simply because they see so many recent inquiries, so keep this in mind. If you're going to apply for any further personal cards, look for ones that only do a "soft" credit pull for the initial approval. A soft pull just grabs metadata from your report without doing a hard inquiry, which temporarily dings your score by a couple points. "Soft" credit pulls generally don't have any effect at all on your credit score. If the issuer approves you with a soft pull then most of the time they'll give you a final approval and might do a "hard" pull in the process.
Look for offers where you're pre-approved or where it says there's no impact on your credit score to apply, and you should be able to avoid inquiry issues this way.
It's possible the fact you're living abroad is complicating your efforts as well, I don't know, but it's certainly something to consider when shopping for a credit card. Learn whether the bank has policies about overseas clients - some might, since it could make it more difficult to collect if you turn deadbeat on the debt.
If you are a new business trying to obtain credit then it isn't easy, unless you're willing to make personal guarantees of the debt, which then entangles you personally in a way you're trying to avoid.
When I wanted to build credit for my new business, I used Wells Fargo, which offers a secured business card that doesn't involve me personally but reports to the major bureaus plus Dun & Bradstreet. By the way, if you don't have a Dun & Bradstreet number for your business, get one. MANY companies check D & B for your business credit when evaluating your application, so lacking a file is showing you have no history.
You need to establish "trade lines" for your business to build its credit profile. You do this by applying for "NET 30" accounts with companies you'd do business with for supplies and services. You can obtain fleet fuel cards for your business - Pilot/Flying J is the easiest one to deal with, and everyone else will give you a card too but will probably want a deposit for the first year until you establish a history.
Building business credit is not nearly as quick or easy as building personal credit history - mainly because it's a much less competitive space than personal credit cards, so there are far fewer options. Not only that, but the reporting process can be slow - some creditors I deal with only report every three months, so it takes time for the first report to post and then for any positive updates to appear subsequently. Don't make the mistake of confusing how personal credit works with what happens in the business world - the rules can be very different. Educate yourself.
IMPORTANT - Whatever trade lines you establish, make sure they report to the bureaus to build your company's business credit profile. MOST companies extending trade line terms don't report, so this is crucial if you're only opening a trade line hoping to improve your business credit.
This is a basic primer, but I hope it's informative enough to get you started. As a closing piece of advice, slow down and quit trying to do so much so quickly. If your business doesn't need credit right now then quit worrying about it and focus on building your revenues. Without being able to show revenues, it's going to be difficult to get ANY creditor to extend credit to your business without a) personal guarantees or b) deposits.
I hope this helps. Good luck!