As it turns out, the only one of those many services I have an account with was Google, and the one I use most often is pseudonymous.
My clearly stated preference was to not link my pseudonymous identities on G+ and YouTube, as well as not to link either to real-world identifiers. I'd actually posted on the custom URL issue (phone number required) a few weeks back. That identifier then turned out to show up as a reverse-lookup to your G+ account. There are people who know me IRL and have my phone number. I'd prefer they did not identify it with my G+ identity.
My clearly stated preference was to not link my pseudonymous identities on G+ and YouTube, as well as not to link either to real-world identifiers. I'd actually posted on the custom URL issue (phone number required) a few weeks back. That identifier then turned out to show up as a reverse-lookup to your G+ account. There are people who know me IRL and have my phone number. I'd prefer they did not identify it with my G+ identity.