Tried the 32-bit, and I'm definitely keeping it. Thanks, hata!
Menu entry for icewm updated fine, SASL is super-easy (that's what brought the request), the look is improved (cleaner) over xchat2, and I do believe it runs faster.
On setting up freenode, I chose the 6667/-+ option. I didn't know that was SSL. As I don't have certificates set up, this was a problem. Was very easy to go back, select the "plain" version and connect. Since everything else was so easy, I'm encouraged to set up the secure version properly when I have time.
My suggestion to force replacement of xchat was a bad one; thanks for silently overlooking it. As you've included a SlackBuild, getting hexchat to grab relevant xchat settings in doinstall or firstrun probably won't be hard. I'll look into that myself later on.
The highlight colors (channel action, channel message, channel message directed to you) for the channel switcher are different than xchat. It's confusing right now, but I think the "new" ones make more sense once I get used to them.