What do you think would happen if an unoccupied residential lot is converted into a community lot but you don't buy a phone booth or a trash can or both? Will the game crash as soon as you try to enter the lot, rendering the game unplayable for that specific lot, or will you just can't get home? Can a Sim drive home with his or her car?

Crazy idea: backup your game and try it. Then you don't have to guess.

You mean, nobody has ever tried it before in all these years since the first publication, or not published their experiences about it?

Yes, people have tried it. You could probably find the answer by searching. Or by trying it.