Those buds are big but they don't look dense, don't take that the wrong way it's part of the strains make up (although can be more down to the amount of topping done). Medium size buds get truly dense, bigger buds are bigger but ''less dense'', think of it as 6 and 2 3's in terms of end weight. The issue is size and surface area, medium size buds have more surface area over all to release moisture so they are less prone to bud rot. Add into that, your set-up will have ''humidity spots'' similar to heat spots. They are difficult to avoid but not impossible. If your general humidity is as you say, and circulation is 24/7 then I strongly feel it is those two issues, humidity spots and big buds. If you grow that strain over and over you may well find the rot appears in the same location. Find that location and fix the problem. That could be done by topping more to encourage smaller buds.
In terms of smoking it, verge on the side of safety. If they are right in what they say, who wants to risk lung infections?, yeah, only greedy fuckers. You can cut out/bin the rot and leave the rest of the bud to mature if it happens again, you don't need to cut the entire site out.
Most people hang their weed in around 65-75f and around 65-75 humidity, or should I say 75 down to 65. When the bud gets crispy to the touch and the stems are that the point of bending just before snapping, then they say is the best time to begin the cure. You can use food grade air tight buckets, maybe 5L/10L size and 3/4 fill them for the curing process. 5 of those, depending on size will cover you for 30/60 ounce. The buckets are cheap, no complaints over the taste yet, as people tend to say glass is ''better''.