There is or was a mod to have a working tv or monitor in-game, never used it so I can't judge if it is possible to use it that way. But one thing is certain, you would need a mod to do this, this late in development I am quite sure it won't be added as a feature by TFP.
Also a bit of warning, an underground bunker isn't easy to manage, you need lots of automatic traps, otherwise zombies will eventually dig through your walls and surprise you 😉
For the zombies you don't need trapdoors. Just use spike traps openly and (very important) plant them flush with the ground. I.e. just dig one-block deep rows of holes and put the spike traps into those holes so that the top of a spike trap is the same height as the ground floor.
Zombies will treat spike blocks identical to dirt blocks so a spike trap on top of the ground would be an obstacle while dug-in spike traps just look like flat ground. And once a spike trap is broken there is only a hole left that will be considered an obstacle as well so the zombies will then run over the spike trap next to it.
No idea if bandits will be intelligent enough to see the spike traps though.