I would think paternity testing would only be necessary if he CONTESTS it, right? You can't tell me they are doing lab tests on every single couple out there???
I might get another legal opinion. I can't believe he can't just admit they are his and have it be over. Seems wacky.
If you move out and DON'T have an order for support, then you are depending on him in his current state to manage his money well enough to provide for you and woo OW at the same time? Seems really risky.
I would get all that paperwork ready to file before you move out.