^ I understand you, but "fleshed out" doesn't have to mean "made to be similar to humans". It means that we could have learned more about how the Great Link works, how it arrives at decisions, if there are any disagreements or if they are, as someone said, "liquified Borg" etc.
In fact, wouldn't learning more about the Great Link have made them more non-human? With no little focus on the Link itself and any Founders other than the Female Founder, we were left - most of the time, while she was interacting with 'solids' - with what looked like a female human dressed like a human, talking and walking like a human, whose main non-human characteristic were her had blurry indistinct features.
Maybe there were some missed opportunities here, I certainly can't rule that out, but I remain a bit sceptical. Part of the issue of course is the basic reason why most Trek aliens are humanoid, i.e. that is the main way to have them come to life, given that Trek didn't go the route of using puppets or CGI (for the most part).
In the case of the FC, the premise was that she took on humanoid form principly to interact with Odo, and thus reluctantly, with the main objective of luring him back to the Link to exist "as he was meant to."
The Link is described as otherwordly, difficult to put into words, transcendant, the language is similar to a description of a deep meditative state or the feeling of a loss of boundaries between the self and the universe as experienced in Zen. In that sense, it's definitely not like the Borg, where individual minds are being dominated by a single collective will. It's more like a mystical union.
I'm not convinced that this state of being could be fleshed out any more than the "peace that is beyond all understanding" can be fleshed out: it's not complicated, on the contrary, it is extremely simple and mostly conceived as the opposite of everyday human experience, with all its identity issues, angst, alienation, etc.
It's an interesting idea to consider, but I'm not sure we needed more information about the Founders' more pedestrian activities (such as communicating with the Vorta, or planning strategy for the war). The Link exists really for two reasons. The first is to provide Odo with an existential choice: he can be at peace or he can be a person; he can love and suffer, or he can not love and not suffer. The second is to serve as the enigmatic gods of the Vorta and the Jem'Hadar. I think the great changeling sea does both pretty well, with the FC as a sort of intermediary.
On a slightly tangential note, bringing another "one of the hundred" into the mix was a brilliant choice in
Chimera, and possibly something that could have been used as a device earlier, since it makes sense that the outcast changelings would be conflicted like Odo and Laas, and thus each one could be potentially fascinating, without diminishing the enigmatic quality of the Link.
EDIT: While I think that the transcendant union of the Link is clearly distinct from the Borg's mass slavery, it is a useful comparison in that the Borg are an example of a race that really didn't benefit from being fleshed out. It was a great concept in its simplest form, but steadily diminished in awesomeness the more it was examined and revisited. I'm suspicious that the Link would have been similar in this regard.
