Florida law is gender blind when determining where the children will live. The children's age and gender is likewise irrelevant. The children's preference is only one of many factors the court considers in determining where the children will live. Children, are, after all, children. An attorney cannot represent both of you.
Most cases do settle short of trial.
Nothing you or your spouse offers in mediation can be used against either one of you if you don't settle your case. Once the lawsuit begins begins, you can petition the court for temporary support. Before the lawsuit has begun, there is no mechanism for forcing your spouse to provide support. Gather all of your financial records and keep them in a safe place. You might also want to cancel joint credit cards and lines of credit and split money in the bank in half.