Diversification is a wonderful idea, one that I doubt has much of a chance at taking root. The island does not, to my knowledge, have any substantial natural resources, and its topography and climate will not support export level agriculture. The cost of transportation probably rules out manufacturing. If it had a viable alternative to tourism (for which it is ideally suited), someone would have already implemented it.

When it comes to rebuilding, there should certainly be an avoidance of wood frame structures. Based on what I have seen, poured concrete structures survived, albeit with damage. Wood frame structures seem to have been reduced to piles of large matchsticks.