Would it be worth contacting the state to find out if they would do this?
My personal feeling is don't contact them. If they intend to levy then you contacting them won't stop it. If they don't intend to levy, then your contacting them may put it on their radar as something to do.
What you may want to do is 1) change the joint account into two individual accounts for the time being and then run everything out of your wife's account, keeping little to no money in yours. You could also just open one or two new accounts and keep no money in the joint account so that if they do levy it there is nothing in it. The objective is to keep no money n any account with your name tied to it.
Do you have any insight into this?
There is no law that absolutely requires them to wait until a certain amount is reached. The arrearage amount just has to be "reduced to judgment" which means that the court has to enter an order with a specific amount in it as to arrears.
Regarding the counter-motion is this something that would be filed by an attorney or could I request my support order be modified due to a change in my circumstance?
You can file the papers yourself but I'd advise an attorney. There are credits you are allowed to take, some income can be classified in a different way, etc. and in 20+ years of doing this I never saw a pro se litigant get the best result they could have. They always missed something that a lawyer would have caught. In addition, lawyer's fees aren't huge for this sort of thing so it's worth the investment, in my opinion. I am a firm believer in people representing themselves if they choose to except for certain types of cases (ex. criminal law, real estate, etc) but there are some other cases where they can represent themselves but aren't as likely to get the same result they would with a lawyer. This is one of those types.