Prigozjin now in control of Russian nuclear weapons in Belarus?

Seems unlikely. The story was that he'd taken over Rostov-on-Don which is on south-east side of the Ukraine, while Belarus is on the north-west side.

He should just switch to the Ukrainian side.

The deal with Putin puts him in Belarus, but scarcely in control of anything.

How much do you expect that they wpoudpay him for his services? If he could get his forces into the Ukraine they might be worth something but the payment would probably have to include immunity from prosecution for war crimes against Ukranians, which might be tricky to negotiate.

What he says sounds quite plausible though. Unfortunate but plausible. Those in the Kremlin are evil criminals with the mindset of street gangsters - which is what they all have been before making it.

If the Kremlin was in it, they would not make Putin look so bad. Putin could have been a strong boss handling the whole situation. Perhaps they need better Hollywood writers.

May be. Or may be they just wanted to make it look real. May be it is about moving forces to Belarus to attack Kiev again from the north. Or make the Ukranians worry about that and allocate forces there. Nuking Kiev can't be masqueraded whatever games they play and they know it so it is unlikely about that, but the rest is possible. The worst thing one can do is to celebrate victory before the game is over.