You can connect with SSL and optionally SASL (as well as cloaking your IP) but this is encrypted to the server. Most of IRC is public anyway though so E2E doesn't make total sense.
Yes, IRC servers can support or enforce TLS for the transport and end users can use OTR (Off The Record) with many IRC clients. IRC uses TCP which Tor supports. There are IRC servers on Tor. Here [1] is an example of WeeChat + OTR. OTR is E2E encryption.
You can connect with SSL and optionally SASL (as well as cloaking your IP) but this is encrypted to the server. Most of IRC is public anyway though so E2E doesn't make total sense.