Not to my knowledge, suspending has never blocked the IP of the suspended user. If this did happen, it would be trivial to evade via VPN anyways, if you’re deaing with anyone even mildly sophisticated.
No, it has never worked that way. You can look up the IP on a user profile to see any matching users by IP though, that’s been a feature for many years.
There is an official browser fingerprinting plugin we’re working on with @dan but it’s still got some bugs to work out.