wow wow wow!
Stop, quiet quite, breathe.
I gave you a way to get and shuffle the list of files, what did you do with that ? I won't make the script for you, I can help you to do it, by giving tips and tracks.
if {[lindex $arg 0] == ""} { set nick $nick }
if {[lindex $arg 0] == ""} { set nick [string tolower $nick] }
timer $timewait [list channel set $cyclechan -inactive]