I was less excited about this until I started reading this thread, then I got excited about the Viashino. However, while someone pointed out the "easily bored" part as potentially problematic in players hands, this part has me groaning.
"Viashino accept, collect, and discard names freely, choosing names that fit their current sense of self or whim. Sometimes they’ll string two or more names together, because they like the sound or because all the names feel meaningful and relevant at the time."
In other words, I'm sure there will be players who constantly change their character's name without warning, just because they can. And I'm bad enough with names to start with, I don't need that headache.
Vedalken are fine, interesting way to hyper specialize in a field, though I wish there were more concrete rules for tool usage to make the guy who chooses Blacksmithing or something feel like his +1d4 to rolls matter.
I agree with people that the Hybrids need a lot more options. I don't see any reason to take the Grappling Appendages, it is an unarmed attack for 1d6+mod with a bonus action at 5th level. It's almost the exact same as tavern brawler (1d6 over 1d4) and frankly if someone is using unarmed, they are likely going monk so the feat is far better for them since it also increases scores and gives some other benefits. No problem with +1 AC or the Acid Spit, though the Acid spit is essentially a cantrip, so a low DC would mean it is hardly worth using except when you couldn't get in range and throwing a weapon is less likely to hit.
Honestly, Loxodon are the least interesting to me, despite having their trunk opening them up to plenty of cool interactions. A Con/Wis race is a cool idea and I like it (Think Firbolg were Wis/Str), but there just isn't enough to hook me on playing the zen elephant.
Biggest thing that annoys me though, and the thing I doubt we could even get away from. So many, many copied abilities. Loxodon are variant Dwarves with some Goliath thrown in, Vedalken are Gnomish Half-Elves, it just kind of grates to see an ability and immediately make that association, even though I know that is on me and not on them to a large degree.