Our Charter [webmasterworld.com] prohibits posts/replies that engage in "company recommendations" since such posts lay the foundation for endless promotional spamming.
Are you only planning to register 1 domain? If so then there are countless registrars that will fill your needs.
Security is mostly a matter password complexity and password protection. There are 10s of millions of domains registered. The reports of "stolen domains" are extremely rare. Therefore it's fair to infer that it's likely 99.9999% safe to register a domain most anywhere SO LONG AS you employ basic safe surfing, PC security, email security and password security practices.