There are so many thiings wrong with your post, but I will briefly touch up on a couple:
In a land based casino a regulator can test any game at any casino at any time. This creates a deterrent to tampering with a slot or any other method of cheating.
Not true. For example, land based Indian casinos in Michigan are not required to be tested or monitored, only the three non-indian casinos in Detroit have gaming commissioners on site.
If an individual plays a slot machine at an online casino the machine does not physically exists.
Just because in a land based casino the slot machine “exists” – it doesn’t mean it operates by “ropes and pulleys”, it also uses software and RNG, thus manipulation is as easy as anything else.
There are online casinos that will cheat you and there are those that won’t. The Absolute Poker deal is a great example how the gamblign websites are tested and not by commissioners who could be bribed.