4) 3rd parties(exchanges, payment processors et al) will be able to use multisig to secure funds so we wont have any mtgox, bter, bitstamp [and so] type hacks which make the coin stolen look bad even though its nothing to do with the actual coin(most of the time). also we wont ever end up in the position of nxt having to think about a roll back to recover 5% worth of coins that got stolen.
having multisig ready for launch was the BEST move the devs could have made.
Yes. If I remember my stolen coins on mintpal and cryptorush...