I like Option 2 - 19 week season just means the same schedule as always, with 2 matchups combined into 1, so we begin and end at the same time as always with the advantage of doing a true round robin now. The playoff #s are just fine as-is too.
The only other one I'd consider is #3 - a 2 week finals could cut down on some of the injury/rest volatility that happens late in the season. But my preference is #2.