Digital Amplifier Questions

I've been wondering the following:

1. Do digital amps benefit from being left on 24/7in the same way the ss amps do?

2. Is plugging a digital amp into a different outlet as your preamp as crucial compared to a ss amp?

3. Do digital amps have small transformers? If so, is distancing equipment from one another less important? (My peachtre Nova Pre/220 look best stacked)

4. When upgrading power cords on a digital amp, do you look for cords that do well with digital gear like your preamp and dac, or do you still go for a beefy cord?

I apologize ahead of time for my ignorance on the matter! Thanks!