Sorry to hear you're so stressed out.  I would say that around 80 or 90% of members on here have problems with their partners - usually the bio Dad - not parenting well or firmly enough because they are scared the SKIDs won't come over any more. It seems like you have proved to your own satisfaction (if not your husband's) that his kids are stealing money - so I would say in future if they come over don't leave any around any more, lock up all your valuables, alcohol and anything else you think you need to. Think about getting nanny cams.  Personally, if a 12 or 14 yr old didn't want to come to our house any more I would advise my DH not to try and force them to come - at that age they can decide for themselves and if they want to resume the relationship later when they have a bit more sense and have seen through their awful bio mother then so much the better. 

If you feel so disillusioned with your DH's parenting that you don't want to let him loose on your unborn -I understand that. In your place I would tell him exactly how I am feeling and why, and then quietly (without telling him) get your financial ducks in a row in case at some point soon you decide to dump him.  

It is mandatory that the skids have a "bad report" ready for the BM when they get back.  Sounds like PAS is going on.  Your DH sticking his head in the sand and not wanting to parent or be the "bad guy" only compounds the problem.

Sounds like it's time to disengage and as far as the stealing goes looks like it will only become a problem if they steal from DH.  

Get nanny cams and don't tell anybody they are there. Especially with the baby coming you want to ensure the babies safety around these children.

Your DH burying his head in the sand is his way of dealing with his lack of parenting and his inability to be a father to his children. Be prepared he won't do the same with your child, if anything he will be harder on your kid.

Definitely a DH problem! Lazy parenting!

At least you now know what kind of parent your DH is, major lazy and completely in denial of his precious snowflakes would do any wrong. I agree 100% with the nanny cams, I wouldn't tell you DH about them either. The next time money goes missing, tell your DH, in front of these little thieves, that you are calling the police, because someone is coming into the home and stealing. Then say maybe the nanny cameras I installed has caught the persons and we can have that person arrested. Then sit back and watch your DH make every kind of excuse under sun as to where the money went, just to protect these brats.

As to the brats telling their BM that no one cooks for them, that DH yells, I wouldn't do a damn thing for them starting now. No cooking, no cleaning, NOTHING, make your DH do everything for them. If the thieves are at your house and DH has to go somewhere, they go with him. At no time are they to be left at your house without DH being home to supervise them.