Yes people think Dark Side has an advantage, which I think is hilarious. I know why they feel this way because you just need to stall the other player, but I disagree I have been playing since I got my copy from the FFG World Championship event and I have yet to loose as light side.
Yep they think the DS has an advantage however, I have yet to win a game with the DS (Ive only played with Sith).
But on the tournament note, regardless of advantages, no one wants to play the same player 3 times, hence the for and against.
You realize that many CCGs, particularly Magic, follow a best of three format? If I remember correctly so did the older Star Wars card games. In fact most games that feature a reasonable short play time follow a best of three format.
Your suggestion has a few major issues.
First, it is needlessly complex
Second, it is meta defining. Under any type of frequently used tie breaker system you'd come to invalidate many decks. It isn't enough for a deck to win, it has to win with a good score to be viable. This would further narrow competetive play.
Lastly, it leads to a false game state. Under that system many times a player wouldn't be playing to win, they'd be playing to lose by a small enough margin as to win the round. This would lead to a many a false situation where the game is not really being played because the tournament rules force a different game to be played. It also means that one bad openning draw could mean a round loss. If you have a bad start one game and get trounced you are then going to lose unless the same thing happens in reverse so you can even the score. A bad start is bad enough as it costs you a game, but under such rules it be even worse,