If you are still in valid F1 status you can file to change to any other visa for which you are qualified. However the fact you filed for...

If you have a fiance in the U.S. perhaps you should just do a fiance visa. Meanwhile, if the facts have not changed, it is not likely the decision...

If the check was not properly completed, CIS will return it to you.

If CIS reopened your I-485, you can refile for your work permit.

It very well could be a problem. It could raise questions about your prior marriage and CIS could allege you committed fraud.

You can file for change of status, but if you are not going to be in the U.S. anyway for 60 days, you might as well just be sure to depart on time.

You answer yes and indicate when you were in the U.S.

File about two years before the five year ban ends, assuming she got an expedited removal, which is not clear from your description.

You can stay in the U.S. during the period you have a pending application for adjustment of status.

Perhaps you are asking if you can substitute other people for an investment visa. I do not see how that is possible unless they are also investors...