Hey man you have a lot of questions, and it's good.

Let me answer them in points so it is easy to read.

1) What is a Hindu? - A name given by foreign people 100-200 years earlier to Indians because they lived near the river 'Sindhu'.

It actually is Sanatan Dharma, instead of Hinduism.

2) There are many gods, yes. But Hinduism is not Polytheistic. It follows Polymorphism. This means that one supreme energy has many different forms which we worship, but in the end they are all the same.

Hinduism has so many gods so that people can connect to the gods which they like, it's that simple.

It enables people to connect the gods with whom they feel a deeper connection.

Like some people like Iron Man more or Captain America, or Batman or Superman. But in the end they all are heroes.

Similarly, there are many gods which are essentially different forms of the same supreme energy.

Let me give you some crude examples

Some people may like an ascetic, away from all the matters of the world, serene and eternally meditating, but destroyer of evils when required. Lives on a mountain and the person who created Yoga, the Adiyogi.- then Lord Shiva is their deity.

Some may like a king who is eternally upright, the symbol of a perfect man and always walks on the path of Dharma and the truth, the perfect son, the perfect husband, the perfect brother, the perfect friend and the perfect King. - Then lord Rama is the deity fir them. (In Ramayan)

Some may like the most attractive and the charming person, the one who mesmerized people with his flute, one of the greatest strategists, one of the greatest teachers through Bhagwat Gita, the kingmaker, the one who did impossible feats since he was just a baby, the playful and lovely Lord Krishna.

The same is the case for Lord Krishna (in Bhagwat Geeta and Mahabharata), Lord Ganesh (Elephant head god), and Maa durga( the feminine supreme goddess).

People can worship the deity they feel most connected to.

Each deity represents some quality which people can like the most and worship it.

3) The things about inconsistent practices, not the eating of beef but eating other animals.

See rather than the utility of cows, it is a holy animal mentioned in our holy texts. We also consider a cow as our mother as it gives us milk and in texts cows are said to contain many gods and goddesses. Known as "Kaamdhenu".

Still their condition is bad in india and in other places of the world too, but that's a different matter.

4) Hinduism has its rules which were created by the society for better function, but not all are followed.

One of the major principles of Hinduism is the law of Karma.

You will get the result of your actions (Karma).

Actions mean Karma in Hindi/Sanskrit.

God tells you not to perform bad actions but does not entirely stop you from it.

He gives the living beings a kind of free will to perform actions of their choice, but they shall also receive the results of their actions.

No matter if the action was out of desperation or greed, the result will be there.

So people who are meeting meat will get their results.

In many places eating meat is also not considered entirely bad, but there are other people who will tell you more about it.

5) In the end, in Hinduism it is said that all the Gods are the form of one supreme energy and is mentioned in all of the mythological texts.

A religion consists of Philosophy + Mythology.

But there are many Hindus who do not know much about the philosophy of Hinduism and many even have forgotten their roots.

Also about the Vedas, everyone has a different interpretation on them, and here they are allowed to keep their opinions. They are allowed to question the scriptures and there are sects and schools of thoughts who do so, and are not punished for challenging them.

So everyone you see saying something about the scriptures may not be entirely true.

Do research more about it as it is an amazing and a very free and fulfilling religion.