1. You get all the premine to yourself, and then create a chain that is longer with more difficulty. If you have all of the possible coins to stake to yourself and have them all competing, you will no doubt be able to create a chain with more trust. Most PoS coins do not have all coins available for staking attempting to stake.

There is a Premine of say 1% in the genesis block but another 35% was created by PoW over a month period before the PoS began.
So the premine will not give you all of the coins only 1%,  this alone should block the attempt?


2. You fudge with the timestamps and using some computation build a chain that would appear to have been created over months or years. There is no way of proving that you created a block 1 year ago other than the timestamp of that block.

Ok, agree on 2

3. Again you can change your timestamps. Instead of actually waiting for the time to stake, you just adjust your timestamp as if that time passed.

How do you account for the lower difficulty from the time where the coins have to wait before staking, this should cause the chain to have a lower difficulty.  Remembering that PoW generated more coins than the original premine.

This whole scenario that I can see being feasible would rely on having absolutely no timestamps, as well as having no connections to active nodes. Either one of those two would make the attack not work. I guess all you could do is trick a first time syncer into being on the wrong fork. It doesn't really do anything of significance in my opinion.