I know missionaries are active in Tuticorin, Tirunelveli, Kanyakumari but what's the problem? Most of the converts are Dalits/poverty stricken people and if they believe they will lead better lives as Christians they must be allowed to convert. Human dignity and standard of life trumps religion, the missionaries provide them both, so what's the harm? Freedom of religion is enshrined in our Constitution and Hindu outfits are free to proselytize also. One of my childhood friends converted to Christianity along with his family. His family was extremely poor but the Church helped them financially, providing for the education of the children. Today they are well to do and the boy has become an empowered man with a great job. I met him at a school reunion a year back and he is still the same, he hasn't become an alien or something like that I can assure you.
Government taking over temples may also be a good thing in terms of social justice. If they can get lower caste people appointed as priests or treasurers maybe it will be more inclusive. Most Hindus don't have a problem with this. If people are aggrieved they can launch a democratic movement to overturn this phenomenon. Indian Constitution guarantees all the rights and most of the lawmakers, legislators, judges are Hindus. It isn't like there is a crazy conspiracy going on to subjugate Tamil Hindus.
Hinduism has always been open to criticism and that is its greatest strength. Atheism and questioning are integral parts of our faith. And let's be honest there are many faults in the current version of our religion and it won't be a bad idea to have public discussions which can ultimately stir a wider debate at an intellectual level. I can't comment on Islam/Christianity, let followers of their faiths handle the matter. But at least in the developed world, Christianity is held to task. If religions aren't questioned it isn't right at least in my view.