Issues

Creating Channels

Creating a channel is weird from a UX perspective. You hit the plus arrow and a text field comes up, but there isn't any indication of how to submit it. Hitting Enter works, but not having a button is a weird UX choice.
Hitting the plus icon again hides the text field but doesn't clear the value
The plus button works as a visibility toggle but doesn't change from + to -. I would add a + button next to the Channels title that opens a mini form with a text field plus Create and Cancel buttons. You can have the Esc key close the dialog, but there should be clear buttons showing what does what.

Attaching files doesn't really show what's happening; there should be a preview, whether link, image, or whatever.
The chat bar should have a draggable area to drop files into.
By default it seems 'react' gives a permission error? It also has a weird assortment of emoji's by default.

The + button acts as a hide/show toggle but doesn't change to - or whatever when it is shown.
Hiding a blurb doesn't clear the fields.
The character count seems to keep the previous count after posting a blurb.
Need a filter and sort feature so you can see blurbs by topic or user.
Need a subscription feature with notifications so you can see what a user is saying
Need a read/unread feature so users can filter out read blurbs
Is the goal to be able to respond to blurbs?
Hashtags?
Sharing and linking to Chats, Essays, and Forums

If this is supposed to be like a BBS forum should there be folders and/or topics?
Need a way to respond
Need a way to see unread posts
Need a way to search, filter/subscribe and hide
Do Forums need admins or owners who can block users, delete posts, etc?
Sharing and linking to Chats, Essays, and Forums

Is the point to show where users are? If so users need to be able to set their location.
Should users only be able to share their location with certain users, or everyone?

Log out button is very large and in a weird spot. Logging out is not a common activity so it shouldn't have such prominence.
What is the purpose of the left-hand tray? Is it for eventually having access to multiple servers, or is it just a logo? It takes up real estate without providing a use. If the server feature isn't going to exist for a while, it should be removed and the logo placed elsewhere.
The user's avatar is very large with some properties around it. This should probably follow the more common convention of being an icon in the top right, with the settings in a properties panel or page. Once set, the user isn't going to interact with the profile that much, so more room should be given to common operations.
There isn't really a theme, or at least the look is very sparse. Setting just a color is fine, but it would be nice to have the ability to set a swatch or theme of different colors, like an IDE theme.
Context menu icons are rough
No server admin panel
Need a way to admin users
History of user actions
Global search to find chats, blurbs, forums, or essays

Might need to look at the tabbing order and make sure everything is tabbable.
Hotkeys for switching between areas
Contrast is harsh for different colors in the theme. Colors for buttons, labels, and icons should be calculated to have adequate contrast with the primary color
Light/dark theme