Most of the following sections is from my talks and +mails with DarkStalker
Aging: Most Verdimm are rather long-lived, compared to our own species. If not killed by a predator or tribal warfare, a Verdimm could die of old age at around 1200-1400 seasons. However, due to the violent and unpredictable nature of Crinos, most Verdimm don't die of old age.. most die violently, and a Verdimm older than 800 seasons is very, very rare.
Time: Note that's seasons, not years -- the Verdimm measure time in seasons. 2 seasons = 1 year.
Tribal numbers: The average tribe of Verdimm numbers in the thousands. The Brusticai are at least 5 times more numerous than the average tribe, but since they're always at each other's throats, it's not such an advantage. The Ret-ti-Senek are about 10 times as numerous as the Brusticai. At least. But they have their own agenda, and rarely interfere in the politics and events of other tribes. For the Lemesech, they're probably not so closely congregated as some other tribes; probably fairly spread out, with their own territories, maybe several small villages. The Venator, for example (BEFORE the infamous battle), have one main village where most of their tribe congregates; they also have several outlying small villages and camps, and various Venator roaming around here and there, so perhaps 50% of their population is typically gathered in the village. (Not any more, of course...) The Tenebrae are another matter entirely. While this isn't known to most tribes, even within the jungle, the Tenebrae were decimated in recent years and there are very few left. Less than a hundred, for certain. The jungle tribes (including the Lemesech) would surely be able to have a better estimate than the plains tribes, and would know that Tenebrae territory and population have been vastly decreased; DS has put forth a lot of effort into not revealing exactly how many Tenebrae are left, however. The Tenebrae have always been secretive.
Everything from here on in is my own stuff.
Ideas I'm toying with for the Dark Convergence and Dea: