What tools exist to determine user account creation trails?
You can check the steemd page of a user for the recovery account. For most people its @steem but in the case of these 2-3 accounts that you've mentioned, they were created by @anonsteem, so you cannot retrace the actual account creator because someone has used a third-party site to create those accounts.
Nice, thanks! I knew about steemd.com but not the "recovery account" feature.
Does the STEEM blockchain contain IP addresses, or other metadata, regarding account creation?
Uh-oh! Sounds like someone is still trying to dig...talk about having no fucking life. You're pathetic. Learn the blockchain ya moron, keep digging, maybe you'll reach China.