Is there a channel for general topics, like "I'm looking for a Linux alternative to omnifocus to keep track of my todos" on this slack?

A channel for non-kotlin things on the kotlin slack? No.

The question is more "here is a programming task all programmers face; I am curious what kotlin programmers use to solve this task"

i personally use markdown files or glo boards synced to github issues

IntelliJ has a // todo: feature which is hnice vbecuase when I click on the item, it jumps me to the relevant file + line number.

#random is about as close as you can really get