I think the importance should follow a left to right direction. If you think the reply is the most important (I do, because promote content creation) after putting it on the left I would expand the icon with a label too.
Adding some left/right padding to all icons will improve usability and UX. 

 More padding makes sense, there are less icons so they should be more spacing, expect further changes, we will keep tweaking until we're happy with the styles