I think that the earliest possible PoDs(and thus, the most effective) would require an earlier dissolution of the BEIC to avoid a government run for the sake of money, and changing the perspective of India in Britain away from a colonial possession and instead a proper crown. I think everything else that you outlined(the tariffs and social/legal equality) would follow in due time and more effectively than OTL if this were to happen. Without going too hard into scenarios where it's only titular a British possession and mostly Indian-ran(ie Royal exile and they go native, a Royal splits India and Britain as separate crowns for his children, etc.) I think the separate crown angle is the best approach.
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Say that a British royal with autocratic or militarist tendencies comes to be the second to the throne, and has an enabling father(so, not the House of Hanover). Severely hampered in his aspirations by Parliament to follow in the footsteps of Alexander, this royal decides to go and find a loophole in the BEIC which in theory, aren't as compromised as Britain proper with respect to what he can and can't do with his military forces as well as being the end point of Alexander's empire. The Royal Family purchases a large set of shares in the BEIC, giving the royal enough authority over the company that he can essentially do what he pleases between his titles and his ownership. So this young royal is off to India with a large contingent of aspiring soldiers and hanger ons, including many second and third sons(this royal has a gift for public speaking akin to his military idols like Caesar and inspires many to follow him in his gloryhounding pursuits).
On showing up in India, the youth proceeds to insert himself into Company business immediately, pushing for aggressive military actions. I'm not too familiar with the history of India so I'm not going to go into details but the tl;dr is that the company follows a similar trajectory under him as OTL and this youth proves to be a wildly successful military commander, leading to bigger successes for the British earlier. His biggest handicap turns out to be the corruption and inefficiencies of the BEIC, so he in turn uses his personal wealth gained in India plus pleading to his father in Britain to pitch in, to dissolve the BEIC by an act of Parliament(this royal has gathered many fans in Parliament which are happy to enable their own homegrown Alexander) and declare India it's own crown with the young royal as it's viceroy. In any other scenario, Parliament would have had India answer to the British Parliament directly, but the romanticism around the young prince's successful(and profitable) campaigns in India have won over too many, and thus they gave him the keys to the kingdom to essentially govern as he sees fit there so long as the profits continue to flow into Britain.
This youth's administration compared to the BEIC is considered a welcome improvement by the locals. While British-favoring, local nobility are still able to rise within his court(really more of a military camp, most of the time) which leads to a far easier time conquering and integrating the local rulers into future military campaigning. The royal's camp is what would eventually become the embryo of a local Indian Parliament on his departure for Britain on the death of his brother, the heir. It's also less focused on extracting wealth, and instead more focused on providing manpower for the royal to wage his wars.
Long story short; this royal is very successful, but Parliament is beginning to regret giving him as much leeway and try to pass laws to limit him, whereas he comes to see his war council of generals, governors, local princes and traders as far more useful to him in helping to conquer and govern India. When he hears of the death of his brother and the request for him to return from his father arrives, the youth is torn and almost refuses, but having a very good relationship with his father, ultimately agrees. Wanting to spite Parliament one last time before he becomes 'powerless' in his own eyes, the royal turned heir to the throne proclaims the creation of an Indian Parliament(which is essentially his war council), giving India local autonomy when it comes to self-government albeit heavily dominated by British noble expats turned generals and governors, and their British and occasionally Anglo-Indian children. With a parting message to finish what he started and to conquer all of India to his Parliament, the royal departs ready to tell Parliament in London to go plough dirt, and that the autonomy of his Indian Empire would be maintained.
Upon his return, tensions in Parliament are high and essentially split between a 'Pro-India' faction(that supports the autonomy of India because they're essentially fanboys, romanticists, economic beneficiaries, and so on of the Prince's Indian adventure that saw a lot of their second/third sons become very successful and wealthy) and 'Anti-India' faction(that is against autonomy from British Parliament, people afraid of the Prince's absolutist tendencies, etc). The Prince does a lot to defuse the situation in stating that he created a Parliament in India, taking a lot of the wind out of the Anti-India faction as it appeases those afraid of the Prince exporting his 'Indian Autocracy' to Britain. It also solidifies the Pro-India faction as it was already a shaky alliance to begin with; romanticism could only get you so far when it was an undeniable truth that Parliament had lost what authority they had over India(which in truth, hadn't been much at the time) and the Prince's well-documented absolutist tendencies were an undeniable fact. Now that many of their children that weren't set to inherit lands or titles had established themselves in India with roles in government? Well, now that just made supporting the Indian Parliament absolutely necessary!
Timeskip to the end of the Prince(now King's) reign, and India is largely subjugated in a patchwork of usurped lands by British lords, local Indian allies that accepted the authority of the British Raj, tributaries, and puppets. A steady stream of British expats has flown into India to fulfill critical roles and earn well compared to toiling in Britain. Feeling his nearing death, the King abdicates his throne for his heir and sails to India one last time. His domains stretch from the very tip of the Subcontinent to the Indus either directly or indirectly, and a ceremony is arranged by the Indian Parliament on the banks of the Indus bestowing upon the British monarchs the title of Emperors of India, in personal union with the United Kingdom, and elevate their company turned kingdom into a formal Empire.
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Rough but I'm not going to write a fleshed out timeline in a sitting. I think the gist of the idea is clear; changing the perspective of India from 'A place to be exploited' to 'A land to be governed' would do wonders for better local governance as you outlined. How you get there is up in the air but I just don't see it being possible so long as the BEIC is in the picture.