HK,
just to clarify my own position.
i think it is good to marry as far removed from one's relatives. in addition to the beauty of getting to know a different set of families and traditions, the intermingling of widely separated genes produces a healthy result. mostly but not always, as handicapped children are born even to these types of marriages. if you believe in God, then you can console yourself that you are a special parent, as only specially gifted parents can handle handicaps.
but, many a times, 'luvv' happens. 'luvv' is blind. and to keep a young couple apart by virtue of sahagothram, even when they cannot trace a relation within generations, is absurd. it does not make sense, when in our own community the practise of athai magan or mama penn marriage is not only recognized, but in many a cases, encouraged.
to sum up: let us do what makes sense, based on each case. ok?