A lot of these objections aren't actually innate qualities of Dravidians, they are cultural things you choose that has nothing to do with your genetics.

Cousin marriage

Your genes aren't forcing you to do this, you aren't married at all.

Eating food so spicy it can make one poop lava. Curries eat food with their hands like uncivilised chimps.

Then eat shredded wheat with a spork if thats what turns you on, your genes arent stopping you.

Bizarre customs like worshipping snakes, literal penises and vaginas, cows and whatnot.

Then don't worship them