First, asserting that we have a two party system is a fallacy. It is not a two party system. It is a multi-party system that is dominated by two parties. That is a key distinction.
I'd have to argue against FM's mud-slinging point, though. With several parties to deal with, it would force the various players to focus on the issues rather than character assassination...there simply isn't enough time/resources to dig into every niche of every candidate's past to find things to spin into mud to then sling as opposed to debating the merits of your party's positions on the issues at hand.
With more than two viable parties, the 270 votes in the electoral college would be difficult to achieve. If it were achieved, it would be a clear mandate. If it weren't, the election would move to the House for a
contingent election, where a candidate must receive a simple majority (26) votes (reps vote as a bloc for each state).
However, the EC discussion is a bit of a red herring WRT the OP.