Actually, with regards to payloads - a bigger issue is how are they are going to deploy customer payloads. Unless they have flat-pack sats in the Starlink form factor, there's no way to get them in or out of a Starship. I think solving that - without compromising the structures or heat-shielding is a bigger concern. Which is why testing the vehicle with a lower mass, more aggressive launch to find out what is actually needed to survive re-entry, comes before actually loading the thing up.