I gotta say, it would have been nice if my Klink had had the option to just knock out Cassidy and get Scotty's goody, rather than playing bartenderess. Fed side, believable. Klink side....errr, not so much.
There's a lot of things about the Klingon side of the missions that don't make sense. Walking around the 23rd century Drozana basically as freely as we do makes no sense. The idea of using holo-emitters to look like D7 cruisers to approach a Federation station in a time when Klingon and Fed tensions were at their height is daft whether you're a Klingon or a Fed.
As another poster so elegantly put it, "Franklin Drake is an idiot." Since the Klingon missions are practically the same, you could say the same of the Klingon Intelligence Officer. (One might suspect Drake and K'Men are sharing information...)
The walking around part can be fudged if you consider how the TOS Klinks looked prior to TMP. As far as the Klink ship near Drozana...well, Koloth was able to orbit his ship around K7 which is even further inside Fed space.