One question I still have is : what is to prevent a user from forcing the generation of a POS block (which is just a flag when starting the wallet now, correct?), jumping offline before the generation is complete and coming back on 6 hours later. Does it attach to the end of the blockchain? or does it insert where the blockchain was when the block was generated (not submitted), potentially orphaning 360 blocks?
He can generate a PoS block wherever in the chain he likes, however with trust reduced to 1 it's useless to do so. And the "no consecutive PoS" rule prevents him from doing any damage even if he has millions of PoS-eligible inputs.