A ROTH is a tax shelter not a tax avoidance scheme and as such the earnings in it are tax free when you make a distribution if you follow the rules. And it can be very lucritive especially if you invest in real estate.
Now can you have a SD ROTH own an LLC the answer is yes, it can be the sole owner or in a partnership. However please talk to your SD ROTH plan administrator to be educated on if you would still need to file a form 990 and pay taxes on the "unrelated business" income.
