Namaste Flex,
The problem with an outsider when they are look into Hinduism they see only the external form of it and a slice of it in time, then they are quite shocked by what they see. Until, they become familiar with what the forms actually mean. For instance the “gods” and you mention Ganesha who has the form of an elephant. Ganesha means “lord of counting/calculation” It is the power described in the Vedic literature which presides over the function of memory. Later, this is given the artistic depiction of an elephants head because of the association between good memory and elephants. Similarly, all of the gods you see depicted with their multiple forms are symbols for profound concepts.
Regarding the caste system. The caste system as it exists within Hinduism only has 4 occupational divisions(there are not out-castes) which is labourer, merchant, warrior and teacher/sage and all people based on their aptitude are assigned to these divisions. The caste system has existed in various forms throughout the history of India both as birth-based systems and merit-based systems. In later times, when the British came into India, they abolished the traditional industries of India in order to replace Indian industry with British industry, as a result Indian industry died out and Indians were impoverished. As those Indians did not have skills for other professions, many of them were forced to take unsanitary jobs like cleaning sewers, toilets and they joined the class of “untouchables”
Regarding children getting married of at 4. This tradition came to India with the Muslims. It is not a Hindu tradition. I think you should bear in mind Mohammed got married to a 8-9year old girl. Another reason for this tradition was that during Muslim rule of India Hindu families needed to safeguard their girls, who would fall prety later on to Muslims who would rape them, prostitute them or keep them as slaves. So in order to protect them Hindu families would make a contract with another Hindu family to marry of their girl, but this would be consumated until both the boy and the girl had reached puberty.
In the traditional Hindu culture there was a set age for marriage based on the system of 4 stages of life. From the age of 8-22 was the age of education. From the age of 22-40 was the age of married life.
Do not mistake the history of India with Hinduism. You need to bear in the mind for the last 1000 years India has been under the occupation of Muslims and then the British. If you want a true image of Hindu society look at the periods of 7000BCE to 1000AD, when India was Hindu and you will see the superior civilisation it had.