$rangetok(): Could be useful.
$reverse(): Personally I don't think of this as something which is particularly useful in a general scripting sense. Sure, a lot of people have 'reverse text' aliases/responders but I'd say it's someting to be left up to scripting. I think half the fun of a reverse-string function in any language is trying to find the best way to do it. I remember there was a big thread about making the fastest
reverse identifier in the Scripting forum once before that I always found very interesting.
$blendian(): Seems like a bit of a niche use for a built-in identifier to me.
$clsid2prog(): I rarely use COM so I've got no opinion on this whatsoever.
As always, insert 'personal opinion' disclaimer here etc. etc.