Not that your threads are annoying /s

No.. not at all.. Roll Eyes

But above MAX_MONEY value's sanity check, how it work?

The source code can be found here: https://github.com/bitcoin/bitcoin.
You can find all neccessary information there.

And what happen pre-mine 100% of coin and still mining reward is not 0?

Well, obviously you didn't premine 100% then Roll Eyes