Yes, many things about blindness are incredibly stupid. Blind people aren't totally helpless. And they do know what they have in their hands usually. At least well enough to drop them.
As for no tells while charmed...
Quote:
A pale green-skinned siren exclaims to you 'Now that you've come to me, I'm not letting you go!'
A pale green-skinned siren walks to you and puts her arms around you.
A pale green-skinned siren whispers something into your ears quietly.
A pale green-skinned siren glows with mystical energy!
Isn't a pale green-skinned siren just so nice?
You now follow a pale green-skinned siren.
A pale green-skinned siren says 'I'll let you go once I get bored with you.'
A pale green-skinned siren moves herself to position (22:M2).
That'd really suck in a situation like that, since she renews it. An experienced player might know one of the ways to get away, but if you're there alone (which you might be) and if you're a relatively new player (which you might also be if you're there), you'd be pretty screwed.
This is just an example of a situation where sending a tell might be very nice, even if it's somewhat bad rp.