hehe.. well you want kick + ban, max online limit ? (i will leave out the start/stop times as you can figure a way to deal with that manually -- ie make the link not work or have a default screen -- for now)
The start/stop time in our previous chat worked a bit better then that. It was a time when you could get in, but it didn't close up after that time. If you were in, you stayed in. If somehow you had to reboot, you got 5 minutes to get back in. I'll get that in myselve again.
Our max online was combined also with an idle kick. If you were chatter limit+1, it would kick a passive user (no activity for x minutes).
once caveat.. php 5, so i can use the zend built in json_encode routine (very fast).
php 5 is fine, that's what running at our host.