Lots of ideas for you!
As a list owner, it would be nice to organize members alphabetically,
It would be nice to be able to add their name when they didn't.
What happened to "direct add members?" Some people are not computer-savvy enough to know how to reply to an invitation.
Groups used to be easy, but now you've made it more complicated.
direct add was discontinued years ago because of widespread abuse. However, if people don't ( want to) have a yahoo-accpount you can send them an invite with the "add to mailinglist" button checked