First of all, this line is breathtakingly beautiful. Thank you for that.
As to the rest of your essay, wow, it's a lot of very thought-provoking stuff. I'm not a practicing medium, but I'm a deeply spiritual person, and I have a few ideas. Feel free to take them or leave them. ;)
1. Sometimes souls feel no urgency in connecting — really connecting — with particular living loved ones at a given moment in time because they have so much faith in the strength of that connection anyway. Likewise, sometimes the power of our own emotion can get in the way of "hearing" from them. For instance, when my cat died, my mother felt her presence far more often than I did, and yet the cat was so much closer to me. I simply got the impression that my mom "needed" to hear from her more than I did, and my cat recognized this.... or, it could be that my cat was trying to contact both of us, and I was too grief-stricken to really "receive" what she had to communicate. So that's one possibility.
2. I do believe spirits have "jobs," but I think our "jobs" on the other side are more like beloved hobbies. If we are all manifestations of the creative force, it makes sense that we'd play the roles that it does: healer, teacher, architect, organizer, etc. In fact, I think that sometimes the jobs we take on on Earth, or the clients we connect with most often, are reflective of what our souls really love to do on the Other Side. The fact that he showed up in "work" clothes might simply have been a recognizable symbol that B was using in order to communicate that he's engaged in "work" on the other side to which he feels very committed.
3. "I'm flying blind" — I can see why a remark like that might cause an incarnate person some level of worry or consternation, and only you can know what he meant by that. But it also reminds me of the idea that the Other Side is free of a lot of Earthly structures and rigid planning. If B was a very "controlled" person on Earth, perhaps his soul is still trying to figure out how to adjust to a place where rigid obligations and expectations don't apply. That's beautiful though that you got the sense he is still watching out for his family. Our souls are limitless, and love gives us even more energy. If he is focused on hanging around and caring for his family at this point in time, I'm sure he is still doing okay in other areas. After all, there is no "time pressure" where he is right now, so it's not like he's neglecting other tasks. Which leads me to....
4) Time doesn't function there the way it does here, as you've pointed out. Since it's not linear, I don't think we need to worry much about the moments when, in our linear reality, we can't connect with them. I don't think it means they're lost or stuck. In a reality of no-time, they are already where they "need" to be, as instantaneously as they intend to be there. This might also be why sometimes they don't feel particular urgency to connect with us in a given moment of our choosing. Likewise, with their larger-than-life perspective on time and on our own activities, they might have different ideas about a "most opportune" time to make the contact and deliver their messages. So that could also be why they stay mum on some occasions when we ask for their words of love and guidance.
All this said, I think all you can really do is send B your love and admiration, highest self to highest self, to assist him with his "pet projects" on the Other Side. If you feel so inclined, you can also send a nod of love energy toward the soul(mate)s that keep him company and assist him there, in case they have an easier time of reaching him with their warmth than you do. B will find his way — and maybe already has. ;)
Wow, didn't mean to write so much, but thank you again for a thought-provoking read!