It seems to me that most things have been covered here. The litanies are shared but not divided, with the first three at Liturgy being done in order of seniority. I think that the Litany of Thanksgiving after Communion is done by the most junior deacon. The dismissal of the catechumens is indeed split between the two, with the first deacon going first, then the second, then the first continuing with 'Let none of the catechumens remain. As many as are of the faithful...' Yes, the second deacon reads the Apostle. After he has received a blessing to do so, he kisses the Holy Table on his way out of the north door, which a reader obviously would not do.
The double censing seems daunting but is really quite straightforward. The main thing to remember is that it follows the same order as a normal censing with one deacon, only it is done symmetrically. When censing the Holy Table, both deacons cense the west side, then they part and one censes the north while the other does the south, then they both cense the east side. Whichever deacon is on the north side of the altar also censes the Oblations Table, while his brother deacon waits for him. Then, while censing the icons and people in the altar, instead of working from one side to the other, both start in the middle (at the High Place) and work outwards. They leave by nthe north and south doors and cense the iconostas in the same way, then the people: starting in the middle and working outwards, symmetrically. Everything else follows the usual order. When censing the icons and people in the nave, one starts at the north side while the other on the south and work their way around the church. They meet in the middle at the west end of the church and together proceed directly to the central icon, which they cense together, before proceeding back to the solea, where they together cense the Royal Doors, the deacon to the south censes the icon of the Saviour on the iconostas while the deacon to the north censes that of the Mother of God. They enter the altar, cense the west side of the Holy Table together, then the priest together, and they give up the censers to a server. Of course, all the while, they say quietly psalm 50 and the troparia of compunction as a deacon would if he were serving alone.
At the Lesser Entrance, the first deacon takes the Gospel, while any other deacons carry the censer(s). Whether they cense the Gospel once in place before the Royal Doors, I'm afraid my memory fails me. Certainly they do at an Hierarchical Liturgy but I don't know otherwise.
At the Great Entrance, the second deacon carries the censer to the priest and receives the aer on his shoulder while the first deacon is the one who kneels at the Oblations Table to receive the diskos. Instead of carrying the censer over his shoulder as a deacon serving alone would do, the censer is carried aloft before him by the second deacon, (not walking backwards and censing the diskos unless it is a Presanctified Liturgy). The first deacon with the diskos makes the first commemoration for the hierarchy as usual, during the procession, and both deacons immediately enter the altar, the one with the diskos kneeling at the south-west horn of the Holy Table and the one with the censer positioning himself ready for when the priest needs it. There they wait for the priest to finish the commemorations and re-enter the altar.
At the epiklesis, I have seen different things. In one case, both deacons joined in the verses of psalm 50 'Create in me a clean heart...' and 'Cast me not away from thy presence', while on another occasion they took one each. From memory, only the first deacon then says, 'Bless, master, the holy Bread' and so forth, but I am willing to be corrected on this point. Certainly, they all join in the triple Amen and join the rest of those in the altar in making the prostration. Afterwards, (and immediately before the beinning of the Liturgy, which I failed to mention above), the customary requests, 'Remember me, holy master', 'pray for me, holy master', and so forth, are given in the plural, ('Remember us...').
I know all of this only for two reasons. The first is that it was I who put together the altar book for my parish and ended up studying the rubrics of the Liturgy from various sources in great detail in order to convey them clearly. The second is that my wonderful parish priest teaches me these things. He knows that his rigorous diaconal training was quite unusual and he is very grateful for it but he knows that not all deacons have been taught to the same standard. In the Greek Archdiocese, a number of the priests were deacons for no more than one day so they do not necessarily have the experience to pass on to their deacons. My priest was trained at a monastery where, if he made a mistake in a litany, when he went back into the altar, he would be punched on the arm and sent back out to do it again. He tells the story that, on one occasion, he made a mistake three times in one litany and the superior of the monastery sent him out and made him prostrate himself before the people, asking their forgiveness for disrupting their worship. This may seem harsh but the result is that I have a priest who gives great care to the offering of the services and knows what he's doing. So he teaches me diaconal service in case one of these other deacons ever visits our parish and find that he needs help so I can direct them without him being distracted from his priestly duties.
I hope it's of some use.