I see this a fair bit and wonder if moving the arrows further apart (formally by PG or using GreaseMonkey in the interim) has been discussed?

I don't have any down arrows, otherwise I would post code instead of just a suggestion.

I absolutely would love to see the arrows resized when viewing using a mobile device.

The solution is not "make it harder to make a mistake" but rather make it possible to change your vote (like Reddit).