Zeppelins lacked the lift and survivability for airborne invasion forces

Could First World War German Zeppelins have been used to carry airborne troops?

No. They lacked sufficient capacity and would become extremely vulnerable when descending to deliver troops.

German airships did not have the numbers or practical carrying capacity to move a meaningful airborne force. Their survival also depended on remaining high, where interception and anti-aircraft fire were more difficult. Descending to unload troops would turn a very large, slow airship into an easy artillery target. The mission would therefore sacrifice the operating condition that gave the Zeppelin any chance of surviving.