Blue Linckia are relatively more difficult, but they are also relatively larger. So if you had a 100g tank, I would say it is marginal. But this is a big tank, with a lot of LR...so I am not as concerned. And you have an advantage because you have access to blues that are not in transport...they are acclimated to your LFS conditions so they only have one jump to make to your system. Acclimation will still be important, but in typical situations, the seastars are being moved from the wild to a wholesaler to an LFS often in a short amount of time...and this is very stressful.
Apart from acclimation troubles, I don't think you would have too many problems with any other species of Linckia either. There are no guarantees, but your system provides just about as much as possible in a hobbyists system. So I don't see a major reason, in this case, not to try a blue. You have a far better chance than most.
As far as not touching them...well, this is somewhat of an old wive's tale, as is not exposing them to air. While these should be minimized, it is not what is killing Linckia, IMO. It is probably easiest for the LFS person to pick the animal up with a plastic bag, if there is any concern with touching it. They can then place it against the glass, or you can observe it while in the bag.
