This protolanguage mixes Ts'ap'u-K'ama with Proto-Eskaleut, which both share different versions of the same three vowel system, the former with contrastive length, and the latter with the Schwa.
Consonants: m, n, p, t, k, q, ʔ, ts, tɕ, β, ð, s, ɕ, x, ɣ, ʁ, ħ, h, l, j, w
Vowels: a, aː, i, iː, u, uː
Syllables: CV
Stress: ???
Writing system: a logography that would simplify into an abjad
Synthesis: polysynthetic
Word order: ???
Noun cases: ???
Grammatical number: ???
Grammatical Gender: ???
Noun classes: a version of the Bantu systems
Tenses: ???
Aspects: ???
Moods: ???
Interjections: ???
Copula(s): ???
Conjunctions: ???
Valency-changers: ???
Number system: base-20
Sets of number words: ???
The speakers could be hunter-gatherers with unique friendships and collaborations with animals, a culture similar to the K'ama peoples and the Eskimos, Aleutians, and Inuits, but with a difference. For taxonomic categorization of animals, I could consider hostility, neutrality, usefulness, and maybe non-hostile as the categories. Dunno about colors, and whatever else could be categorized among basic terms. Or the terrain the speakers would inhabit.
The Inuits use a vigesimal system, and a number system was created for it during 1994 C.E., with that system spreading throughout the Inuit areas of Alaska, though the Canadian Arctic tribes and peoples might still be considering it if they didn't start using it already. These con people might do the same thing, creating something that would go along with their abjad. Whatever reputations they might possess for speakers of other languages might be something to consider.
Some sound changes I have in mind are the formation of ejectives, the fortition of fricatives to stops and semivowels to fricatives(via vowels mutations), labilization of alveolars, velars, and uvulars, and that's it for now.
