She's poor because
1. Shion the goddess of poverty has been residing in the shrine secretly for a long gime
2. Nobody wanna climb a mountain and give money to the shrine maiden that can't remember her god's name
She's not really that poor and absolutely not starving, but her financial instincts are always wrong.
Reimu's biggest power is being a Mary Sue. She's almost as lucky as celestials, which means she's unironically always supposed to win in the end, she knows it and reminds of that when she loses a battle. She never tries to get better and lies only on her abilities given from birth (i.e. flying etc) just because she's from the Hakurei clan of shrine maidens. Just a reminder that Marisa achieved everything, her power and knowledge, all by herself. Reimu doesn't have notable personality traits except for being lazy (working only when forced by duty of protecting people from dangerous youkai for free or by Yukari) and money-hungry (a fan-service exaggeration by Zun). Also she can talk to gods and summon them, she can seal demons, she can float through reality ("Fantasy Nature" spell, making her ABSOLUTELY
View attachment 13485 when she wants).