To the first paragraph - There may have been a lifelong bond in ways beyond the ken of men and angels. It may have been strongest shortly after His death?
The second - If we have a human spirit, then I imagine that some form of influence is possible by those who perfected the abilities of the spirit.
The third - Well yes it is conjecture because I'm only wafflehead. 3 days must have some significance, true. Jonas was in the whale's belly for 3 days and three nights and Jesus said He like Jonas would spend 3 days in the earth. It was said that at the very moment of His crucifixion that all the graves were open and many bodies of the saints that slept, arose.
The trinity, which is not literal, but still has some truth regarding the connectedness of G.d, His Manifestation and the connection of divine guidance via the Holy Spirit may be hinted at via this arbitrary 3 days.
As for grief and anguish, let's say that after 3 days the disciples became assured and steadfast.
