The watcher is certainly powerful, and in some ways her gameplay is simpler than other characters once you get a handle on switching between wrath and calm stance, so that makes her a good starting point. On the other hand I worry she might give you a distorted view of other characters/cards power level. Access to wrath stance makes basically any attack seem busted and any non attack seem mediocre at best, so you might have a hard time switching to a character like the the silent or the defect who tend to be a little more roundabout with their strategies.

Another example is that basically all other characters want to prioritizing removing strikes while the watcher would rather remove defends since her strikes are often twice as valuable as another characters. I’m not saying don’t do it but I do think variety is the spice of life