To begin with, the noun rank has nothing to do with the adjective rank.
The noun is of French origin (possibly Frankish ultimately) and originally denoted a series or line of things (range has the same origin); then specifically a line of warriors or soldiers (whence our 'rank and file'); then the successive lines, the first, second, third ranks, and so forth, in which soldiers are deployed; and finally, by way of one's position in the front, middle or rear rank, one's grade or standing.
The adjective rank is of Germanic origin; the precise line of descent is obscure but it seems originally to have denoted various attributes of the noble warrior: proud, haughty, rebellious, strong, vigorous, full-grown. In ME the martial connection faded and the word became used particularly of undesired and excessive strength, vigor and abundance; it was extended to vegetation (we still speak of 'rank weeds') and to loathsome behavior and smells (O mine offense is rank says Claudius); eventually it acquired such a strong negative connotation that came to mean 'corrupt, foul, festering', and eventually simply 'extremely (offensive)'.
See the Oxford English Dictionary, 1st edition.
When your source writes of rank dishonesty it probably does not intend any one of these later senses but (at some level) all of them simultaneously: extremely gross, corrupt, loathsome dishonesty.
From thefreedictionary.com...
tight-knit - closely and firmly integrated
a tight-knit team (that's over 900 hits in Google Books)
Note that plain tight is also quite common, particularly in reference to a band (group of musicians) whose playing is highly coordinated. In many contexts, tight-knit may also have strong overtones of bound in love or friendship, but that "emotional" dimension isn't required for the usage.
Best Answer
The phrase all along is often used in contexts where some duplicity or mistaken understanding is involved.
This entire time, you have been pretending to be interested in birds, when you're really interested in Martha.
We developed a theory that the butler had killed the duke but it turned out that the duchess was the one who had killed him. We were mistaken from the start.