Incredibly important! There are certain forums where I need to write every post first in the offline editor just because the timeout is way too short. This conditioned me to do anything offline that takes me longer than 10 minutes to recreate and just copy and paste it when ready. Same with blog posts, etc. It might be illogical, but when my machine crashes it is my fault and I get over it quite quickly. But if it feels like it is your site's fault that caused the trouble I am most likely not giving it a second chance.
not at the moment, but it's a great idea. We oppose vendor lock-in of any kind - so we'll definitely look into adding offline access and export features. Thanks!
For now deleting and browsing through guides is not yet possible. Obviously both will be added very soon.
We thought about Ace, actually, but we weren't sure yet if people will end up using stps for source code. We will probably look further into this in the future though.
Thanks!