Starship Couriers

An idea for To Trek Again
Why do you need a whole Galaxy-class ship to ferry people around? Not only does it seem an inefficient use of resources, it also suffers from having to respond to nearly any emergency under the stars. So, for all your important diplomatic needs, why not have a small, very fast ship that's only job is to get a skilled ambassador on-site as quickly as possible? No diversions, no distractions.

The Premise

Set during the TNG/DS9/Voyager eras, a small (think oversized Danube-class) ship that's 90% engines, plus barely tolerable quarters and the minimum in equipment carries around an important Federation ambassador to time-critical missions. Likely set within the interior of the Federation, as border and foreign missions prefer to fly the flag from impressive Starfleet ships.

The Characters

The ship would only carry the number of PCs (maybe +1 in case of guest stars), and the PCs would have to be multi-functional. I'm thinking roles like: Pilot, Intelligence Agent, Engineer, Soldier, Diplomat, Doctor. Each PC would choose two of the roles and would work together as a team to complete the missions. The Diplomat could be an NPC or a PC.