Aren't you an optimist!!
The solutions I have on offer are not liked very much by anyone here. It is somewhat like the current US healthcare debate, a single-payer medicare for all kind of system is the best, but there is more chance of sun rising from the west than this hapening. US congress may even enact a medicare-for-all system but this forum will not look kindly on my suggestions in this regard. Even people who tend to agree with me in principle on this topic think my ideas are Utopian

(just a friendly dig)
Even so, since you insist, let me suggest a few small steps for any interested person to look into:
[1] Go outside the bounds of traditional "wisdom" about caste issues and try to find out, with an open mind, why Brahmins and Brahminism are disliked, more like hated, so much in Tamilnadu.
I have spent my entire life in Tamilnadu and I have close friends in DK,DMK and AIADMK but none of them are coming out with proper explanation why they are indulging in Brahmin bashing. They started from justice party days `brahmin bashing' which they are practicing on competitive oneupmanship basis. Only few are still holding onto their regular habit of Brahmin bashing and majority don't have any any anti-brahmin sentiment.But still they don't want to be seen openly supporting our community.
[2] If there are mixed marriages in the family give your loving support to the couple.
This is a hypothetical question. Let us decide on the case as and when it happens
[3] If you know of youngsters wanting to marry outside the caste talk to the parents and try to be supportive of the youngsters.
Again it is a hypothetical question. Let us decide as and when they want support for such an incident. I have three children coming up for marriage during the next five or six years and if they come out with such a proposal, let me decide on the merit of case. The `merit of the case theory' is applicable for within TB community also
[4] Talk to Dalit activists from your poorviga village and find out how you can help.
I am personally in touch with the daliths in my native village.Infact when land ceiling was introduced, my father gave up the lands to daliths which is still being appreciated. But other caste hindus are unhappy that Brahmins are supporting Daliths
[5] If you are a doctor or a lawyer, see whether you can offer free clinics for the benefit of poor Dalits in villages.
TB community of our native village is still running a school eventhough more than 90% of our community has left the village. Only other community members are studying. The land belongs to TB community and if we want, we can get the school derecognised and withdraw the land but we are still running the school for the benefit of other communities.
(Don't do #4 and #5 in the name of any religious or caste organization.)
I am sure other more creative people of this forum can come up with much better ideas if only they are so inclined.
My personal experience is daliths don't have anti-brahmin attitude excepting a few. But caste hindus have a hidden agenda. They don't want brahmins to prosper and at the same time they don't want daliths to come up. Lot of caste hindus have obtained SC community certificate from Tahsildar in Chennai City & suburbs and are misusing the previlages meant for daliths. Only dalith upliftment will create a better environment. But Dravidian parties don't want dalith upliftment and are still keeping them illeterate which I am sure is going to change in the next few decades
Cheers!