Do we want to have gendered nouns/adjectives?
Maybe some kind of noun classes that aren't tied to gender?
That seems a good idea
Based on the words we have so far, I think the three options should be "-is" nominatives, "-ez" nominatives, and "-in" nominatives
How should those decline, then?
Tbh, imo, "-is" and "-ez" are far too similar sounding to really support different sets of inflections over a longer period.
are they though? remember also that final "-is" would be a stressed syllable and final "-ez" would be an unstressed syllable
Ah, did not know that. Then I agree, stress + voicing is probably enough of a distinction to keep up differences. Would the classes affect only adjectival declination, or also changes in nominal inflection? If the latter (take Latin as an example), here a few ideas on how nominative endings could tweak the ideas of declination we have at this point.
"-IS" Nouns (Class I or whatever)
berís
berál
berúx
berén
berír
beról
bérux (if no differences in writing with our genitives, why not a difference in pronunciation?)
berón
"-EZ" Nouns
hábez
hábel
hábeg
háben
habzír
habzól
habézug
habzón
"-IN" Nouns
sulín
sulinál
sulinúx
sulinén
sulinír
sulinól
sulíx
sulinón
Before completely critising all of that, hear me out: "-ez" endings in singular more often than not are "e", simply because stress there sits at the first syllable, and with a lack of schwa unstressed vowels in natural languages often move towards "e". This unstressed e is lost completely in the plural when the stress moves behind it onto the ending, safe for the plural genitive "ux", where it sits, on all three declinations, on the penultimate syllable (which is also the reason the unstressed u is deleted completely in the "in" declination, with "sulínux" being simplified to "sulíx"), to differentiate it from final (or initial) stressed singular genitive "úx".
The "g" in the genitive endings of the "ez" nouns is a sort of voiced version of the "ux".
I very much like evergreen's idea, btw.