No one else has got the other two yet, you wanna have another go?

Alright so my conlang's a bit of a mess so you'll have to forgive me for some of these things, but I'll do my best to setsumei suru.

CONS is construct state, which means that it's close to の but sort of "in reverse". This is to say, when a word is put in the construct state, it means that the word is modified by the following words, rather than modifying the following words itself. This is a feature most associated with Semitic languages — the go-to example is {malika|queen} vs {malikat|queen-CONS} {sabaʾ|Sheba} for "Queen of Sheba" in Arabic — but the construct state is also found in a number of other languages, Western Micronesian languages have them too for instance. So "kyertev _____" really means "a thing loved by _____", and when this phrase is the subject of a verb, it really means "_____ likes to..."

—Oh, I should clarify, the literal meaning of kyerte is just "a heart", a word with which it Definitely Isn't Cognate. So basically if we're translating things even more literally it's maybe more like "Rin's heart goes alone..." for "Rin likes to go alone..."

As for the other features:

1. Not necessarily obligatory, or at least I don't think of it as obligatory, but you're on the right track to think that kav anskagunska he is an idiomatic placeholder — it's really just the equivalent to "one day". Sometimes I question whether not marking tense in verbal inflections actually was such a good idea after all!
2. The lemmata for those words are an and gun, and yéne so yegune was really just supposed to mean "the two of them together", I wasn't necessarily thinking consciously about which character was yéne and which was yegune. There's no form of obviation in this lang in any case, and there's a healthy class of pronouns including interrogative pronouns, indefinite pronouns, personal pronouns, demonstratives, among others, all the classics.
3. The pronoun šo is used as a complementizer and relative pronoun (very European!), and can in general be used as a pronoun pointing to the previous clause, which is the meaning of šo in the phrase so šo. This phrase so šo most often means "thereafter" but may also just mean "as well", because my lang is perhaps a bit more vibes-based than it should be.

Then as for the orthography, Ňň represents the /ŋ/ sound (modeled on Turkmen), Šš, Žž, and Čč represent /ʂ/ /ʐ/ and /ʈʂ/ respectively (these three are indeed modeled on Slavic languages like Serbo-Croatian), and then Ǒǒ represents a vowel in the vicinity of /ø/ for really no other reason than that it would feel "inelegant" to suddenly use a different diacritic for that letter. The doubled versions of these caroned letters replace the caron with a double acute accent, so N̋ /ŋː/ S̋ /ʂː/ Z̋ /ʐː/ C̋ /ʈʈʂ/ Ő /øː/. Non-caroned letters all double by just adding a single acute above them.

The letters Aa, Bb, Ee, Ff, Gg, Ii, Kk, Mm, Oo, Pp, Ww are really pretty boring. They make exactly the sounds you'd expect from the IPA. Uu is normally read as /u/ but if next to another vowel may become /w/. Vv normally makes a /v/ sound, but can make a /w/ sound when used as the construct state suffix — officially only before consonants other than glides or another V, but in practice I often end up just reading the construct state suffix as /w/ almost always regardless of what comes after it. Yy normally makes a /j/ sound, but when followed by the aforementioned preconsonantal construct state suffix, /jw/ will fuse into /ɥ/.

The letter Qq is not normally used. The letter Hh makes a /h/ at the start of a word but a /x/ elsewhere. The letter Jj makes a /ɖʐ/ sound.

The remaining letters are the alveolars: Dd, Ll, Nn, Rr, Ss, Tt, Zz make the sounds you'd expect, Cc and Xx make /ts/ and /dz/ sounds respectively, and all of these when doubled will palatalize: D́d́ /ɟɟ/ Ĺĺ /ʎː/ Ńń /ɲː/ Ŕŕ /rʲː/ Śś /ɕː/ T́t́ /cc/ Źź /ʑː/ Ćć /ccɕ/ X́x́ /ɟɟʑ/