Also used when telling a child she/he is too young for whatever the context.
We are talking of one person jere, tum, are we not? So why is chote used which is plural
तुम always conjugates that way even if we are talking of a single person. The same is true for आप.
Sometimes the answer is small and other times the answer is short. How do we know which one is correct?
Both are correct. Depends on the context.
Someone with better Hindi creds can correct me, but I think this only matters in English as to which one you use. Hindi doesn't seem to make a distinction, at least not using the particular word "chota," between small and short.
Short is generally used in context of height while small is nearly applied in almost any context (excet height)
Chote/chota can mean both small or short depending on context.
Any capital letter you need to put if you do not put ans is wrongs.