Re #2: yes, clutter (icons don't solve the clutter problem, and HN's design is emphatically textual), plus there should be a bit of a speed bump before favoriting much as there is before flagging.
> clutter (icons don't solve the clutter problem, and HN's design is emphatically textual)
Even if you don't want to add more icons, you could still improve the visual elements you have (the vote arrows.) Links with title tags around Unicode glyphs would arguably be more textual than empty divs with gif arrow backgrounds and no accessible text fallbacks.
I still think they should work something like this: https://jsfiddle.net/84q0zecv/10/ even without the colors I think it communicates the states well, and is visually not that different from what the site already has.
Re #2: yes, clutter (icons don't solve the clutter problem, and HN's design is emphatically textual), plus there should be a bit of a speed bump before favoriting much as there is before flagging.