If you have already filed for EB-5, it will be difficult to obtain a B-1 or B-2 visa, unless you can show strong ties to your home country, e.g., owning a business or being employed in a long term job, as well having a wife at home and children in school. It is better to obtain the B-2 visa before you file for EB-5.
On the basis of filing an I-526 petition as the principal investor, the children of the petitioner can still apply for a visitors B-2 visa to temporarily visit the U.S. for pleasure .
You may run into the problem of dual intent. The EB-5 program is for permanent residency. The B visas are for temporary visits. One of the requirements for the B is to show intent to return to the home country. How can one show that intent with a concurrent process to obtain U.S. permanent residency?