What is a NEET? Is this board only for NEETs?
A NEET is someone not in education, employment, or training, thus the abbreviation. This board is for everyone, it was called NEET as a homage to /jp/.
I am socially awkward/I don't leave my house, does that make me a NEET?
It does not. While it is common amongst NEETs you don't have to be socially awkward or a shut-in to be a NEET, and vice versa. Someone who does not leave the house is called a hikkikomori - they might still work from home, making them non-NEET.
Does self-employment, being a housewife or doing chores make one non-NEET?
Someone who does those things is still a NEET, as it is not socially recognized as being employed, and in most cases is not a source of income.
This is more of a request than anything - but please don't pretend to be a NEET to appear "cool" or be spiteful to someone who is not a NEET. It belittles people actually going through it, and discourages those who are not NEET to contribute and speak out. This board is NOT a secret club.