There's one intermediate conclusion to reach first, though - I'll also argue that
That second conclusion seems a bit counter-intuitive, but its support is all mathematical.
Let A=The number of protown players alive
Let B=The number of proscum players alive
Let C=The average power of a protown player
Let D=The average power of a proscum player
Then AC=Power of the town and BD=Power of the scum. (AC)/(BD) expresses the balance of the game, where a higher number means the town has an advantage and a lower number means scum has the advantage (1 would mean that the game is perfectly balanced).
Now, let's say the mod were to decide to randomly off a player. The game balance after the decision is made (but before the decision is executed) is:
(odds of hitting a protowner)(New Gamebalance after hitting a protowner) + (odds of hitting a proscummer)(New Gamebalance after hitting a proscummer)
[ (A) / (A+B) ] [ ((A-1)(C)) / (BD) ] + [ (B) / (A+B) ] [ (AC) / ((B-1)(D)) ]
[ ((A)(A-1)(C)) / ((A+B)(B)(D)) ] + [ (ABC) / ((A+B)(B-1)(D)) ]
[ ((A)(A-1)(C)(B-1)) / ((A+B)(B)(D)(B-1)) ] + [ (ABsqrdC) / ((A+B)(B-1)(D)(B) ]
((A)(A-1)(C)(B-1) + ABsqrdC) / ((A+B)(B-1)(B)(D))
(AC)((A-1)(B-1)+Bsqrd) / ((BD)(A+B)(B-1)
(AC/BD)((A-1)(B-1)+Bsqrd) / (A+B)(B-1)
(AC/BD)(AB-A-B+1+Bsqrd) / (A+B)(B-1)
(AC/BD)(B(B+A)-1(B+A)+1) / (A+B)(B-1)
(AC/BD)((B-1)(B+A)+1) / (A+B)(B-1)
...and we know that 1/(A+B)(B-1) + 1 is always a number greater than 1, meaning that the new game balance = the old game balance x some number greater than 1. Therefore, the new game balance is more favorable to the town than the old one.
The obvious next step from this conclusion is that those who have the power to make random deaths happen and are protown should do so. The vig can do exactly that,
(Side note: The whole "random deaths are good for the town" thing is actually a good argument for suicide vigging, too - it shows that gaining a "Free" lynch is, in fact, always a good thing.)
So. There's no such thing as an overeager vig - All vigges should choose to kill every night, anyways.
The most ironic thing about all this is that overeager vigges are more powerful than normal vigges, as the player playing the role is forced to make the correct strategic decision every night.
Pie