they will change the server seed on your account or just simply change roll number to make you lose. You can see it while doing manual bets - after few winnings on high payout the next roll takes a bit longer than the previous - after that frequency of your winnings is dramatically changed.
Any roll made with any server seed is as random as any roll with the help of nonce. Anyway, your point is void, even if there are delays(ever thought it was your network/computer?) , the server seed is not random changed after such delays. And you still have the "freedom of choice" , i.e you can select a different side.
I would disagree with this. If PD was changing the server seed without notifying a user then this would be defacto cheating (I would personally doubt that PD is doing this though). Even though a player can decide to change from High to Low, their betting pattern should allow PD to guess with a good amount of certainty what the gambler's next bet will be, at least in many situations.
Also although a roll with a server seed/client seed combination is random, if you know both the server and client seed then you will know the outcome of the roll before hand, and a specific server seed could be used that they know is going to result in a loss for the player.
Delays in rolls in itself is not suspicious nor is it a sign of cheating, as there are a number of legit explanations for this.
As of now I would say that this thread is nothing more then the OP blowing smoke, however if actual evidence were to be presented that the server seed was arbitrarily changed then it would look very bad for PD.