Answers (ish):
obliged is "make legally or morally bound to an action or course of action"
<em>"doctors are obliged by law to keep patients alive while there is a chance of recovery"</em>
unfortunately, it's been a while since I read the book, so I don't know the exact answer
since the book is told in a way where adult scout is remembering parts of her early childhood, this naturally makes her a generally unreliable narrator as memory fades. so, the question is asking, what in the book can be known to be reliable, so not entirely bound to scout's memory.
a multi-dimensional character tends to mean when a character has many sides to themselves, like personalities, secrets, etc. A good example would be Boo Radley
