OP,
What you have described sounds a whole lot my my inlaws.... (my MIL)
I completely and TOTALLY understand!!!
I know EXACTLY how you must feel.
So, know that this is coming from somebody who is not out to judge or question you about how you feel about the situation!!!!
I do have to say, that this is what scares me the most....
Your husband actually comes home and repeats his relatives questions and snipes to you.





This is just wrong, and is really amost scary.
I am just being point blank, and trying to tell you what you need to hear, no matter how painful it might be. The truth does sometimes hurt... But, there does seem to be issues with your husband.
As I have said before, I have BTDT with a husband who is too close to, and too scared of/controlled by his parents.
And PS:
NO!!!!! cleaning out a kids ears when one is there for a short visit/meal is NOT, NOT, NOT appropriate... This is not offering a tissue for a runny nose, or being helpful.... OP, do not let anyone here tell you that it is okay for anyone else to physically cross the line with your children's body..... You are right to be concerned and to take all of this very seriously.
You really need to address this with your husband.
I know that I could never, ever, get my husband into any kind of counseling. But, it sounds like this has been an ongoing problem, and your husband continues to respect them, while disrespecting you.