Sorry, I've been pretty busy trying to square away this server relocation stuff for my own server, I've been a little absent...
I'm worried that having a blank value for max size will lead to enormous avatars
It will happen
so how do I edit the pages to remove the height/width wherever avatars are displayed?

In scripts/showflat.inc.php:
Find:
$postrow[$i]['Picture'] = "<img src=\"$Picture\" alt=\"\" $picsize />";
Replace With:
$postrow[$i]['Picture'] = "<img src=\"$Picture\" alt=\"\" />";