We have a drahk player and these questions came up first ed. Matthew replied and from his replies we pieced together the folowing campaign rules for the Drahk. Now remember, these are from my memory, which can be faulty at times.
1. A mother ship or carrier can replenish at fleet headquarters
2. Carried ships can not gain experience, they are part of the Mother/Carrier
3. Surviving raiders et.al. are not lost. But rule 2 still applies. I assume they will be assigned to other ships as the orphans settle in with a new mother/carrier.
4. Can't be deployed separately. Reiterated in the latest addition.
This still makes them powerful in campaigns, but the inability to gain experience helps keep that in check
Skipper