Why? I can understand someone being interested in strategy games. I'd like to know some reasons for the interest in anthropomorphic metazoans.
Was metazoan really necessary?

Just to make me look it up?
It's like the example I gave Cheezy - put a stick figure next to a picture of some great, epic battle. You'll likely reject the stick figure and say the second one is "beautiful" and "well done", and overall, "appealing." Furries, I imagine - as in my case - are the same way. We have an interest in anthro animals, and as a result will often pick the animal over the human in terms of character design. They just naturally seem "cool" to us, I guess. This interest and liking of animal designs is about all we have in common across the board, however.
That doesn't bother you??
Nope, not really. We're an odd group.
A fair comparison, but I suppose what strikes me about "furry fandom" is that there very little of what you'd call "unity of purpose". While something like conservativism, or punk or geekdom or whatever all seem to be united by a loose set of roughly aligned core values, "furries" seem to have little more in common than a shared interest in what is loosely termed "anthropomorphic animals". To be honest, it doesn't seem to be anything more than a matter of slightly arbitrary self-identification, supported, perhaps, by the apparent co-existence of many of the aforementioned interests in many "furries". I suppose that is true of anything, to some extent, but it seems particularly blatant in this case.
Perhaps it'd be better to compare furs to a culturally-diverse nationality rather than an ideological group. People of those nations only really have their citizenship in common, despite their differences. Furries, likewise, have differences, but have that "citizenship" in the furry fandom to link them together.
Also, a couple of less nit-picky ones:
How important is the concept of the "fursona" throughout the fandom, and to what extent is there a shared understanding of the concept?
Fairly important and widespread. Not all people have fursonas, but many furs make them, or if not that, will nonetheless make an animal to act as their avatar. Whether you would want to actually be your fursona varies.
Why does the typical fursuit seem so cartoonish, when most anthro art depicts far more idealised figures (and often more heavily influenced by Asian comic art, rather than Western cartooning). Is it merely the only variety commercially available, or is it representative of some divergence in aesthetics within the fandom?
Probably just the limits of finances at work. Most furs - being humans in reality - aren't rich and probably can't afford the best suits in the world, but will try their best. Think how a suit a company designs for promotions will look FAR better than one made for commercial purposes. It's easier to draw something perfect than it is to manufacture a suit and make it just as perfect.
I can draw a furry character pretty well in a matter of minutes with no cost at all besides the time. Contrast that to trying to add all those realistic details to an actual suit, all the measurements, all the MONEY and time involved, etc. Obviously much harder to make a suit than it is to make a perfect drawing.