OK, sorry...to pull everyone, kicking and screaming, back to the actual topic...
The Soviet Union actually had something of a cruise industry. Not particularly successful by western standards, but it did exist. Found this interesting website:
http://www.simplonpc.co.uk/SovietPCs1.html
Based on what I've read of SFU history covering the periods of relative peace between the fighting we all know and love, it seems commerce did travel with relative freedom across borders (subject to typical customs/ import/immigration regulation of course). If goods could be moved for a profit, why not "people". In peace time, Klingon cruise liners might operate both within, and outside Klingon territory, carrying not only Klingons, but subject races and/or "foreigners".
Its interior would be distinctly Klingon of course, suitable both to remind Klingons and Subjects travelling abroad of where there loyalties lie, and to impress foreigners with the "wealth" and prestige of the Empire. It would serve the purpose of raising capital, and muscle in on the foreign cruise liner markets.
I could also see the ship serving a more devious purpose. The establishment of a normal "legit" cruise line across the Klingon border would create opportunities for the infiltration of agents into other empires. Likewise, it might create a ready pool of foreign "hostages" in the event of a crisis with another empire. Finally, it could serve as an intel collector, moving more freely to foreign ports of call than other ships with a large number of eyes and ears, gathering information on the planets of potential enemies.
Which gets you to the security station. I think the security team would serve several funtions, not all of them traditional as Klingon ships go:
1. Keep the crew from jumping ship in a foreign port.
2. Keep an eye on any foreign passengers, both for counter espionage purposes, and as possible targets for exploitation.
3. Support for any covert Klingon agents aboard.
4. Security for the Klingon capital sunking into this seemingly wasteful and risky venture.
5. Security for any high profile Klingon passengers.
6. An obstruction to deter forign customs agents from getting too nosey.
7... I could keep going, but all you need to do is go read a few James Bond novels...
I realise the idea of Klingon Cruise Line seems like a contradiction in terms, but it would have uses. Its funny, I could almost see a piece of fiction based on this outwardly absurd sounding idea.