If a reorg occurs, what happens to the operations that get reorged out and are not already included in the new chain? Would they need to be broadcasted again or would they automatically be re-entered into the mempool?
If it is reorged out it will need to be broadcast again, but you cannot just re-broadcast the same operation. You'll have to give it an updated valid branch field in the operation, since the original branch no longer exists.
Also, by default it seems items time out of the mempool after 60 blocks. I believe that 60 blocks start from the branch you specify, but not 100% sure, would like a dev to comment.
Also, I think that the figure 60 was supposed to be a constant, but don't see it in the context/contents RPC.