What you are asking for here is an invitation for griefing behaviour. Raid leaders will bring a group through to the final boss, kick everyone and invite their friends who did not do any of the work to get there. I have seen it happen in other MMOs .
Sorry but this is a horrible suggestion.
I have seen this as well.....I have also seen a group get all the way to the final boss and 1 member needs to quit, feed the baby, take a nap ect....
Fix the god damn UI ! The thing is a piece of crap . You have to move around to get the prompt to pop up , and then when you activate it , hope that it works. Cryptic your UI is a piece of **** . This game will never go to X-box or PS 3 , so implement a proper UI for PC 's or open it to Modders that actually can make it work.