Nuclear or not, if Trump possessed top secret docs he should face penalties. If he had some and they are now missing (re: the empty folders) he should be responsible for that. Just like any other private citizen.
His legal team of course will be fighting to delay any trial until the GOP is back in power, they know all this will be wiped away. THAT is the thing to fear here...well, that and this unqualified judge with severe conflict of interest that is already showing that she is inept (or in team Trump's pocket). The 11th circuit (iirc where appeals go) is packed with Trump appointees too.
If Trump gets a fair trial and isn't found guilty so be it. The problem is that he may not get a "fair" trial, he might skate due to judges that support him and a shitty system that lets Presidents pardon anyone they want, for anything.
Again the question to ask is: where would any of us be after those docs were found in our house? Being questioned in a tiled room most likely. Instead Trump is "golfing" (or whatever that mafia style meeting on the golf course was....)
And if you could find an honest "Conservative" (look under any unicorns you encounter), ask them how they'd feel if the FBI found these docs at Pelosi's place, after giving her months of notice to turn them back in. I'm sure it would be "why are they pestering her at her private place", right?