Welcome to the DHC! First off, when dealing with family, I would encourage you to compromise and eventually just live with it. I know you don't want to hear that, but what they do in their life is really none of your business. I say that, no in a disrespectful way, but I have to deal with this with some of my family. I have relatives that feel strongly towards others in our family who do not work or "mooch" off others. My thought about this is, yes it does stink and I don't like it, but what can I do about it? It's their life and all I can do is be there for them. I may not agree with what they are doing (or lack of doing) but the bottom line is they are family and that means something to me.
Now on your situation, like BB said, if their names are on the deed I find it hard to believe you can do anything based on them not having a job. I don't see how a lawyer in court could have an argument based on you not wanting them there just because they are there frequently as a result of not having a job. The bottom line is they are on the deed, therefore they are doing nothing wrong being there. It sounds to me like there is some greed coming into this situation. Once again, I do not mean any disrespect, I'm just saying what I feel.
Ultimately, I would encourage you to talk to your family and hash out a plan or a deal. I can tell you from first hand experience that going behind their back and taking legal action (or trying to) can make things REALLY bad-- not only for you but for EVERYONE in the family and especially for those who wish to remain non-sided. Family is something you can't buy. I realize you wish your family members were people who gave back to society, but sometimes you don't always get that when dealing with family.
Good luck and once again, I mean you no disrespect. Let me know what happens....
...and on that day when my strength is failing, the end draws near and my times has come, still my soul will sing Your praise unending, ten thousand years and then forevermore!