What Happens to Monies Owed if I Should Die Tommorow

In other words up until fairly recently he was actively seeing the kids? Then I'm sorry, but if the worst were to happen (and let's hope that this question never actually has to raise its ugly head in real life), Dad would be first in line for custody.

IF he wasn't willing or able, then your choice of standby guardianship would quite likely be followed by the court. If that did happen, the guardians would then be entitled to file for child support from Dad.

With regards to already-accrued arrears, recovering those would be up to your estate. CSE can take it off their books, but that doesn't mean the debt is actually erased. It just means that CSE won't enforce or try to collect.

I just want what's best for our kids. Their dad has a long history of drug abuse (and arrests), and if he ever got himself together he would make a pretty good dad. Would the courts order him to randomly drug test for a while?

Not a chance unless you have recent proof that he's using. And even then, you'd usually have to show that the drug use is endangering the kids.