What about llSetKeyframedMotion, which the wiki states: llSetKeyframedMotion is implemented in terms of frames and not real time. To avoid a drift from the expected positions and rotations, use times which are integer multiples of 1/45, e.g. 20.0/45.0, 40.0/45.0, 90.0/45.0, etc. with a link to the forum?
You could use an overhead titler (an attachement displaying the name you want over your head) and a RP tool (a HUD relaying what you type in a channel, like /2, and displaying your quote with the name you choosed) In role-playing, your avatar name is not necessary your character name. Maybe your community is not used to thise tools (evenif they're common in others). You may try them anyway as it can help other players to lift the confusion.