Yes, Discord only allows bot developers to become verified (which is required for bots to be in over 75 servers) if the developer is able to verify their identity via Stripe, no alternate process is provided for developers outside of the supported country list.

Presumably they have alternate verification processes for such countries as are not supported, when they deem it relevant to their business to do so; I expect it’s handled more as a case-by-case consideration and less as a well-defined policy, but you could still ask Discord Support and report what they at back to us!

Probably, and that's a good thing. The amount of fraud and bad actors outside of those supported countries represents a significant threat to Discord's user base. They might accidentally block a couple good developers making bots to help people along the way, but in doing so, protect the greater good.