Yes it can take some time for USCIS to deposit the check.

Your husband can apply for the tourist visa on his own by establishing the strong basis for his travel.

Best to contact USCIS directly to inquire through service request.

Possibly but you can correct at interview.

You will need to appear for the immigration court date and best to consult with an attorney prior to this day.

The interview will be held based on where you physically reside.

As you are in the US you may file for adjustment of status.

How old are your USC children? Consult with an attorney for further guidance.

Best to consult with an attorney in private to discuss your case in more detail.

It can be an additional 3-4 months thereafter.