Just screwing around wiht the query, completely untested and i'm half asleep so i don't know if it'll work, but you could try something similar to:
Change:
$query = "
select t1.USER_ID,t1.USER_DISPLAY_NAME,t2.USER_TOTAL_POSTS
from {$config['TABLE_PREFIX']}USERS as t1,
{$config['TABLE_PREFIX']}USER_PROFILE as t2
where t1.USER_ID <> 1
and t1.USER_ID = t2.USER_ID
and t1.USER_IS_APPROVED = 'yes'
order by t2.USER_TOTAL_POSTS desc
limit {$config['TOP_POSTERS']}
";
To:
$query = "
select t1.USER_ID,t1.USER_DISPLAY_NAME,t2.USER_TOTAL_POSTS
from {$config['TABLE_PREFIX']}USERS as t1,
{$config['TABLE_PREFIX']}USER_PROFILE as t2
where t1.USER_ID <> 1
and t1.USER_ID != 1
and t1.USER_ID = t2.USER_ID
and t1.USER_IS_APPROVED = 'yes'
order by t2.USER_TOTAL_POSTS desc
limit {$config['TOP_POSTERS']}
";
Adding the uID of users to ban (in this case, the line below):