Oh, the case of the 6 blind men describing an elephant.......(and going a step further and screeching out to the world that only the dumb will have different descriptions !!)
On your queries:
The NREGS is a massive scheme (unlike the REG scheme of Maharashtra state) and is intended to cover the entire BPL population. Thus, the resources needed are so great that only central allocation can make it happen.
Yes, Kerala workers (drawn from among the poorest) are engaged in construction jobs in the gulf. And they are not working there for nothing. They continue for years there and save enough to achieve a string of personal objectives, education of children, construction of a home (often a higher end bungalow when compared to what their counterparts in other Indian states who cannot make it to the gulf in such large numbers can ever manage !), marry off their children, set themselves up for old age.... So, that only reinforces the point that Kerala is the most accomplished among Indian states in terms of real poverty alleviation.
About other Indian states: Despite being 'blessed' by having been free of left rule, the poor in many of these states wallow in misery, slave on other's lands, avoid sending their children to school and instead make them work along with them to add to the family income, have never seen anything like a decent school or a public health centre in their lives (though these states have earmarked huge allocations for such objectives)