Question about blackjack machines?

Is a blackjack machine a statistical simulation of real blackjack, with honest odds?

Or is like a poker machine or slot machine, in that it can be set to payout whatever percentage the owner chooses to set it at?

It is whatever the programmer decided to write it as. And completely unregulated. Could be an honest simulation, taking a small cut for the house. Could secretly take a cut for the creator of the script, without the owner being aware of it. Could be crooked as you can imagine...

Not one of them out there that I have seen will let you see the source code, so there is absolutely no way to tell a rigged machine from a fair one.

It's easy for the owner to tell if the writer of the script is keeping anything for themselves, it would be in the transaction history. As for whether they are fair or not, it's true that they could be written any way the author wants them to be, but there is really no need for that. A non-rigged game already provides a good return to the owner. It's true that you can't know for sure without reading the code, but I believe that the tables by the well established builders are legit.

To correct something you posted about poker machines, non-rigged poker machines bring up cards at random, just like they would happen if you were playing with a real deck. The owners percentage payout is changed by changing the amount that each hand pays back. For example, changing the payout for a flush from 8x to 7x (or whatever they are set at) increases the percentage that the owner will keep.

Its as close to the real thing as the scripter felt like making it.

That includes odds / etc.

Whatever odds they felt like putting in there are the odds.