I'd say national TLD's are to be avoided, if they're known to be anti-whateveritisyou'redoing. ".com" is kinda difficult given the US just claims it.

Other than that I don't think anyone cares. The idea is that you're easy to find, just focus on that. Robustness... Onion and bit are resilient, more so than a bare IP address, so that's worth it /if you're expecting domain name troubles/.

.io is hip right now, but it's like 35usd instead of ~10usd, and it feels icky-hip not cool-hip.

Can't wait till we get 1-N domain names; where a domain name is like a tag and up/downvotes and a web-of-trust regulate ordering. Democratic, distributed, semi-/inconsistent in a good way. If you pin an identity, use a certificate! Way better to use identities that way anyway. Have governments certify that a certain entity (cryptographic entity) is the natural or legal person it claims to be, allowing any government to do that. Totally different ecosystem though. That's life :/