1. Auto limit
2. Syntax highlighting
3. Multiple queries can be written in the editor; spaces separate them. This seems to run the first query in the editor afaict.
4. Key bindings (I discovered that cmd-enter appears to run the query, but I didn't see these documented anywhere nor are the configurable.)
Also, stylistically it's a little spare. Alternating textures per row might be nice.
I do like the live table editing and the quick auto-querying of tables (though, there are cases where I might not like that.) Another thing I like is the query history -- one thing that would be nice would be to highlight those queries that failed due to syntax errors in red or something, to help you read the list, but even more importantly, a search feature (like Sublime's cmd-P).