(Don't now what happens when the chain is longer and most of the replayed transactions will have more confirmations on the Clashic Chain than on the BCH Chain.
Nothing. The blocks are incompatible due to the difficulty difference. If you run BCash, BClashic blocks are invalid. And vice versa. Neither the length of the chain nor the accumulated proof of work matter. Nothing will happen after reaching these milestones.
The transactions are valid between the chains so they are replayed unless you have tainted coins that exist only in one of the chains. All the mined blocks after the split are tainted and all the coins that moved only in one of the chains. And all the coins that have tainted parents.
If this coin gets traded, it will be fun to watch the BCash narrative. Because it is not a fork of BCash, it's BCash that is a fork of BClashic