One-Shot Killing a Raid Boss? Difficulty Slider?

did they add this because of the Infinity System? I mean one of the Creators said you could kill a raid boss in one-shot but it would take 1000 years to reach that much infinity points... if that's the case.. then are they saying that it woud take 500 years to kill a Midtown/Hightown/ICP Boss? :)) Probably Not.. I mean I'm 69/80/40 3.5k omegas and I can solo a cosmic boss..
Anyways.. With the Infinity System being (you know) infinite... is that why they decided to make a Difficulty Slider? I mean.. like really thank goodness they are making one.. do you know how annoying it would be to just one-shot everything?! think of how annoying that would be to other people who are questing or something like that
Speaking of that.. how will it work? your own difficulty slider? are they saying although multiple people will attack the same boss.. each person's boss will have a different HP, Attack, defense, etc.? don't know how that will work.. that would be cool.. well I guess we will just have to wait until Test Center...