UCC does not imposition of Hindu law. Far too many muslims of OTL pak and Bangladesh in India now.
That's the catch-22 with UCC. There is really no middle ground enrage all with something completely foreign like a Christian like code or other European laws, basically a highly modified Hindu Code and enrage Muslims and a significantly modified Muslim Code that enrages Hindus and to an extent the Muslims. There is practically no middle ground that can satisfy all but plenty of way to make everyone unhappy.
2.)Nukes estimate Bhabha is only an estimate
Dr. Bhabha gave a two year estimate to Nehru in 1962 which was considered optimistic despite India have operational Uranium Mines, Nuclear Reactor and starting work on a power station the following year and a nuclear test for "peaceful purposes"being on the cards from at least 1958.
It is a euphemism for Bose wanting to establish a working navy so he could take those islands. This will be the source of conflict between the states and India. By the time Truman goes and the next administration comes, India will get closer to the soviets but as the Chinese commies win, both India and USA will have to reevaluate their choices.
Building a navy from the scratch would take decades and certainly not a couple of years. The officers corp is practically non existent. Ships need to be purchased. Officers and technicians trained, docks and ports developed, shipyards made. It certainly cannot happen by the time Admiral Nimitz comes whenever that is. Again US asking for a naval base in Kolkata is odd as it's a river port. A far more suitable place would be Waltair(Visakhapatnam) with its excellent natural harbour like Karachi has for the Soviets.
The railway line is not government project it is being undertaken by the Jammu and Kashmir princely state. India claiming that infrastructure has been built does not mean that it is reliable. In a conflict with the Chinese(who have a similar infrastructure), these roads and the rail line will play a crucial role.
Look the airport is quite feasible at Damsung or with significant work at Gonggar but a road isn't and certainly not with the J&K state budget they can hardly afford to build a line into the valley. The 1902 or the 1907 proposal can be done probably but no more and even that would take years to build. 1800+ kms is just the distance from leh and at least a decade of work is needed before any line reaches Leh. Again developing the mountain tracks to all weather roads to Ladakh will itself take at least a couple of years. Maintaining 40000 troops in Tibet is going to cost more than maintaining 150000 troops in the plains due the logistical challenge. The best strategy is to open routes through Ladakh (Demchok), Mana pass in now Uttrakhand, Nathula in Sikkim, Tawang and another in eastern North East Frontier Agency towards the Amdo region of Tibet. U-Tsang is the only region that can be held on against the eventual Chinese onslaught. Kham has to be abandoned and the deciding theatre would be Amdo. In case Amdo becomes untenable then the Tsangpo watershed with its snow clad mountains would be the ideal and excellent defensive position guarding the Brahmaputra valley and the U-Tsang region. The exact border North of the Tsangpo watershed is upto you but it would be at a point in where the Chinese and Indian power projection capabilities reach its limits (likely the point beyond which the other power can deploy greater air power possibly just north of the band of Tibetan lakes) If Nepal agrees then the Korala border crossing, the lowest and widest of all would later become the main artery connecting Tibet and most able to support the movement of mechanized forces. Only Demchok would nearly as capable as this crossing. Holding onto Karakoram in the North, North of the Tibetan lakes in the middle and the Brahmaputra watershed in the east gives an excellent defensive position for India and the rump Tibet.
Lastly buddy, I am greatly appreciative of constructive criticism.
See the pace at which India is developing infrastructure and making reforms is too too much too too fast. Time would be needed to get back into international financial system, achieve internal stability and make economic progress. It is very possibile that it happens significantly faster than OTL but not that fast. Your India is probably doing a decades worth of work in within the short wartime period.
Bose wasn't a totalitarian unless he contracts the syndrome of "absolute power absolutely corrupts" and even ITTL he is acting like a consensus builder. Hopefully India will become a democracy otherwise inevitable corruption would rot the system. People show that China, South Korea and Taiwan developed under Totalitarianism but that actually wasn't the case. South Korea and Taiwan was received the access to Western markets early due to being an ally and their educated populace developed economically and the growth was sustained under democratic rule. China had that meteoric growth due a specific set of circumstances where the US relocated it's industry at the end of the cold war. Bose's India is just him, no party, no military just him and the other groups coalescing around him for the time being and that's a dangerous combination.