Remarks on the Caste System
The caste system was first mentioned in Manu Smriti (and not Vedas). The ultimate objective was to construct an ideal society in which everyone is happy. The caste of a person was meant to be decided based on a persons inherent demonstrated qualities, and not based on a persons birth — I assume that each person was meant to decide their own caste.
This would suggest that the modern form of the caste system is wrong, because it has become a sytem based on ones birth. This is politically significant, as this form of caste is considered as one of the biggest draw backs of Hinduism by others. Outside of Buddhism and Sikhism, nothing much has been done to follow the correct practice of the caste system.
Remarks on Scripture
Is it not possible that there is a scripture prior to Vedas? A scripture that explained only the core principles? At present we find people with power get their things done. But the honest and truthful people do not get their things done (except enlightenment, which can be pursued independently). Is it not possible that Vedas (and also Manusmriti) were manipulated for selfish motives?
Mahavakyas (Tat Tvam Asi) in Vedas are the core of Humanity. Then why are we giving higher importance other parts of the Veda (like caste system)? There are many points in Vedas, Manusmrithi, etc. which restricts a human being's freedom (such as freedom to choose the work); whereas Hinduism is meant to promote freedom. So are not these scriptures wrong?
Remarks on Practice of Hinduism
Hinduism has always been perfect. Then how come it is not perfect now? Compared to any other country, India has been following Vedas better. Then, why is it that U.S., Germany, etc. are evidently superior to India in terms of scientific knowledge, wealth and general ethics?
Unless we start practicing the right way of Hinduism, won't the world risk losing Hinduism? Other religions might try to eliminate / convert Hindus. Some will convert out of free will — Hinduism has declined by around 3% since 1961, and Islam has grown by 3% in India [reference]. Ultimately, is there not a risk that future human being might not even get a chance to understand Hinduism?
"Sati" was never a practice mentioned in any of Hindu scriptures, including Vedas and Manu Smriti. Neither did Shiva/Sati tell anybody to do this. It was followed in India by "people". The religion had nothing to do with this practice.
As to the status of women: their proper status is same as men. There are references to certain restrictions on women, but these restrictions might have been manipulations made by people. In Hinduism, everyone is equal.
We could have done much better. When, one by one, people came and tried to destroy Hinduism (including human beings and resources — Nalanda etc.), we Hindus (including Brahmins, Kshtariya, Vasihyas and Shudras) did not do enough to protect people. Our actions were not right. (We did not act as much as we should have.)
Our discrimination was wrong. We did not know whether a visitor (Mughals, Britishers) came for our good/bad. We applied "Athithi devoh bhava" and forgot what Krishna says in Bhagavad gita about selfless action. At present, most (95%) of Hindus (including Brahmins, Kshtariya, Vasihyas and Shudras) are selfish and do not follow their conscience.