Word - Hindu has 2 meanings - One who lives across Sindhu is called Hindu.
One who can do Dohan (duh) and get the best of it like butter from milk is a person who is Hindu.
So, flexible, versatile and scientific thinking is something which makes a HINDU
Hinduism is a way of living(lot of scientific and natural living is possible). Please ignore superstitious believes. Hinduism is not though with strict rules.
Hindus never discourage other religious practices. Remember, hindu is more towards spiritualism than materialism. A very deep within you can be attained.
Vedas,Upnishads ,Puranas,Hindu Scriptures
The term UPANISHAD means sitting down near or sitting close to. They form the core of Indian Philosophy. They are the concluding portions of the Vedas. The teachings based on them is called Vedanta. They are an amazing collection of writings from original oral transmissions, which have been aptly described by Shri Aurobindo as the SUPREME WORK OF THE INDIAN MIND.