OK
Well, I do not know any details about your business project; but be advised that neither Nebeus nor Zen are just crypto exchanges. Yes, you can convert crypto to fiat there and vice versa but they also run a lot of another important business. I am not much familiar with Nebeus but as Zen is concerned, their primary businesses are payment operations, (fiat) FX and cards. So they might not perceive you as a direct competitor.
I understand.
See above. „I do not have competitors. I have only potential business partners.”
(If you convince them that you are bringing some business that is otherwise unreachable for them... why to refuse?)
In EU – no idea. Bank Frick LI, Seba or perhaps Sygnum (but the onboarding there is really not easy) CH; as already advised...
Pretty expectable. With Seba or Sygnum you can expect the same or more.
Well, in such a case you might have only an option to start with some EMI like Nebeus/Zen/Intergiro and move forward later; or to accumulate more capital....
Good shot!