I would really love to see a feature where a character can toggle on /off the making of attacks of opportunity.
As it stands a caster can be in the middle of casting a spell and will stop in order to make an attack of opportunity, even if invisible or in sanctuary which obviously causes the spell to not be completed (although not lost I think) and if invisible you now loose the invisibility.
I play exclusively on RP PW and most of them allow the old sling with no ammo work around as long as a clear note is in the character bio so other characters can be aware not to RP the sling. But some servers do not allow this and operate a strict wysiwyg which imo is lazy but whatever its their server.
Now a means to toggle making AoO on/off would be greatly appreciated by many of us who regularly have characters that for one reason or another would not, could not, don't want to make AoO which as often as not are against the archer near you and not the spell caster about to nuke you anyway... lol