They'd be crazy to rig their random number generator. Too many people would have to be in on it, as it would have to be rigged in a way that benefitted 'their' players. If it got out it would destroy a projected 4 billion dollar asset practically overnight and people would go to prison. Why would they do that when they don't need to?

This sort of rumour is easy to start when you're a weak player who keeps losing and you get disgruntled, that would be my guess.

There are players who use robots, but Party try to detect them and remove the offenders. If someone seems to be too good then you can always leave the table and find another.

Party wouldn't pay people to play, as they have 20,000 people online at any given time, often a lot more. This may have happened in the past when they just started up and hadn't reached critical mass. It's also possibly a misrepresentation of the fact that Party will sometimes give very active players a rebate on their rake and that they pay reload bonuses and other freebies which could be construed as 'paying' someone to play, but only in the way that casinos 'pay' high rollers to play. In other words they give incentives to lure players. I'm all in favour of such incentives!