You really must stop this. Being hurt and angry is one thing. Behaving in a vindictive and reckless way is something different.
Yes, your ex chose to leave. Yes, it is very painful. Yes, it is life altering. The thing you constantly seem to gloss over is the fact you do have a choice on how you react to all of this.
Like the under the table pay/tax issue, the WIC issue has been going on for some time. You were fine with her getting WIC until you needed *something* else to retaliate with. Just like you were fine with her pay/tax situation until you thought you could use it to hurt her like she hurt you.
The one thing you failed to realize is either situation could not only come back to bite you (because you knew about it long before you reported it, resulting in you being equally as guilty) but what it could do to your daughter. Do you really want your daughter to have TWO parents wrapped up in costly and lengthy issues because you decided to be vindictive? If your ex has her WIC taken away your daughter loses out.
All you do is blame. You blame your ex, OM, your ex's dad and now the parenting class. How has that worked out for you thus far.
You act horrible then you become angry when your EX refuses to engage with you. If the tables were turned and you sat in a parenting glass with somebody that mumbled and grumbled under their breath as you said you did, would you be keen on spending additional time with them?
You keep saying this is all for your daughter but I don't believe that. If it was indeed for the sake of your daughter you NEVER would be acting like this. Period.
It is crystal clear why your EX avoids you like the plague. You said yourself just two posts up you behaved in a mean and spiteful manner because you did not get your way. And you even took it a step further by BLAMING your ex for this behavior because she would not "give a little". Maybe at this time she *is* giving all she can. Or, maybe she has zero desire to give you anything. Whatever the case may be you must accept it for what it is. But you don't. Instead you pursue and smother her then BLAME her when she retreats further.
I don't believe this is about saving your R anymore. You simply want and need control. You try and control your ex and when that doesn't work you take extreme and vindictive measures to try and regain control. So far that strategy has almost gotten you arrested, put you square in the middle of a custody battle, pushed your ex further away and now you have resorted to filing complaints about her benefits.
You haven't done any work on you. Not one bit. The teacher at the class told you to treat co-parenting as a business. That as good advice as it removes all the emotional junk and allows you and your ex to focus on the most important job at hand, raising your child.
We all backslide and make mistakes but you go far beyond "the usual" and I find it disturbing. We all hate the justifications a WAS uses but you, as a LBS, seem to do an equally good job at justifying very bad behavior. Nobody has made you do anything. You have chosen to react terribly.