I take it you have to run a script in the email while reading it with the Yahoo web client open, so using a local client is safe. (I don't open mail from people I don't know anyway... and even then, scripts and images are disabled in my client.)
I was able to get email@example.com, so not only do I still use it, but I pay $20 annually for IMAP/SMTP access. I use Thunderbird or iOS Mail to read my mail and only rarely and occasionally use the web client to read mail.
However, their stupid security settings require that I sign into the web client every two weeks to re-enable IMAP.