Not sure if Dharma was trying to exploit the island. I believe they wanted to use it for good, but could not or would not involve the Others who wanted to keep the island pure.
I was using the term "exploit" more in the sense of development, make use of, make the most of as opposed to taking advantage.
I would hope their intent was for the greater"good" but the one element we miss to substantiate this is who funded them? It is apparent this island was picked for the "natural" resources or "supernatural" resources it held.
Dharma would have to be somewhat duplicitous about what the true intent was or how would they get people to come there and work?
Juggy you are right the "others" were allegedly causing issues with Dharma, ergo the fence. I also think that Smokey was there when they Dharma crew was there, I am 99.9% positive about this.