Why, it can still be multi-rotor, and even capable of bigger payload with the same battery.

The air drag from the balloon will be an issue. OTOH the motors could be run at low power when cruising and at high power when speedy maneuvers are required.

The size will definitely be bigger. But if we talk about professional-grade drones (for video reporting, etc), they are large and expensive as they are. Improved safety and thus easier time getting allowed in to a worthy event might be more important than a lean package.

Could the airship configuration be a recovery mechanism? IE, instead of having a parachute or airbag to soften the landing, have compressed helium release into an airship and then continue powered flight with whichever motors remain?