how/where to get/work with flour fresh from the mill

I've done a fair amount baking of sourdough hearth breads using standard recipes from Reinhart, Glezer, et al. I've always used standard flours from KA, such as their whole wheat, white whole wheat, rye blend, bread flour, Sir Lancelot high gluten, and others. Recently someone brought me some "sifted stone ground whole wheat flour" from Littleton Grist Mill in NH. I found I had some trouble with it that I suspect revolves around the need for malted barley flour addition, possibly aging, and possibly hydration differences, as well as needing to figure out the protein content and adjust for that, as well. But, it did get me thinking about exploring the availability of flours straight from mills in retail quantities and motivated the questions below.

 I was wondering if anyone has experience buying flour from mills in retail quantities. After some google searches, I found there are a few mills or suppliers, such as Heartland Mills, Homestead Mills, Wheat Montana, Littleton Grist Mill, Giusto's, etc., that seem to offer "organic", "artisan", "stone ground", "roller milled" flours. These products sometimes are "sifted". The descriptions on their web sites vary in terms of the information offered about protein content, degree of sifting, whether it is enzymatically balanced, and whatnot. I'm interested in advice and thoughts on what questions to ask the mills, what typical processing and storage is done at home once the flour arrives? Also, when is it necessary to add malted barley flour and how much should be added? Also, I've read about flour needing to be aged if it is "green" from the mill. When is it necessary to age flour, and how is this done at home? Is further sifting done at home? If so, what equipment do you use to sift whole grain flour and where can you get it? I would love to know of any experiences, advice, thoughts anyone has on this topic. Thanks...