Rules when 2 people pray side by side

Rules when 2 people pray side by sideCategory: GeneralRules when 2 people pray side by side
Praying brother asked 2 years ago

Salaam. Two questions regarding when 2 people pray next to each other:
1) Is the salah invalid if the imam is to the right of the person following him? I read that it is preferred for the follower to be on the right side, but what if he is not?
2) Sometimes I lead a brother in salah who is extremely tall, and I am short. Even though we stand with our heels at the same place, when we do sajdah, his head is ahead of mine (i.e. ahead of the imam) because of how tall he is. Is this okay? If not, what is the solution to this issue?