Most of the time, you’ll have to dash cancel twice to cover ground for the OTG with Samurai’s Edge. Which can be done by tapping forward twice (dash), cancel with crouch, and then dash again but perform Samurai’s Edge before the dash animation is finished. You’ll notice Wesker sliding while pulling out his pistol. This process is also called “wave dashing” if done repetitively.
But to answer you second question, after Wesker’s Air Series I press both assists buttons (given I only have 1 bar) after OTG. He’ll perform Phantom’s dance by himself…
But if you’re looking for more information check out this Sub Forum… http://shoryuken.com/forum/index.php?forums/wesker.92/
There’s always new info and ideas being posted… Good luck!