Sure you can fast
Sure you can run them together
Is either a good idea? No.
If you couldn't diet, why do you think you'd be able to fast?
Why do you want to do sdrol with the DNP? You're going to combine one of the harshest, most toxic oral steroids with one of the harshest fat burners? Why?
How about you try low dose (200mg) DNP for a long run? You won't get the cravings, you won't feel like complete ass, you'll still be able to work out decently well, and you'll be able to function in real life without being a weirdo that is constantly drenched in sweat. You'll (should) be able to stick to a diet with this dose. If you're already in a decent deficit, the DNP adds to it quite nicely.
I don't even know what sdrol has to do with all of this.