Weekends can count toward the 21 days. However, they don't always count or at least they might change the time computation. Reviewing the applicable court rule on time computation is always the best / safest way to determine due dates.
It seems as though you might not be well qualified to practice family law. If you agree, you ought to meet with an Oakland County Family Law attorney. (I recently met with a surgeon because I didn't feel well qualified to practice surgery. It just seems like...
If you've lost confidence in your lawyer, you need a new lawyer. You might be able to get some or all of your money back from your lawyer. Schedule a meeting to discuss that with the lawyer. You can get more information at: www.OaklandCountyFamilyLaw.com
Although it isn't possible to give you specific information about your case because much more information is required to do that, I will tell you that your wife is VERY wrong. You should meet with an experienced divorce lawyer soon. If you cannot afford a lawyer, the judge might order your wife to pay your lawyer. You can read more at: www.OaklandCountyFamilyLaw.com
Grandparents have VERY limited rights in Michigan (and most other places in the US). In addition, it is wise for you to have some court orders in place regarding custody of your daughter. Meet with a Detroit area family law attorney for additional advice.
Children can never make their own decisions. Once they become an adult, at age 18, they can make their own decisions. Before age 18, for instance at age 15, the youngster can voice their desire to the judge. The judge then decides what to do with the child's opinion and how much weight to give it. There are other considerations for the judge to look at before deciding custody. Definitely meet with an experienced family law attorney in Oakland County right away.
Either parent making threats before the child is born is bad for everyone. A family law attorney can counsel you on how to obtain a court order for custody, parenting time and child support. Planning for this before the birth is a fine idea.
Both parents will have rights to the baby. Courts generally don't tolerate playing tug-of-war with kids.
Children's Protective Services should be contacted if there are serious safety concerns for your son. If there are drugs present or if there is violence in front of the child, notify law enforcement. You can also file a parenting time complaint with the Friend of the Court. Your attorney can also ask the judge to modify the parenting time order.
Filing a default, entering the default, scheduling a pro confesso hearing, drafting a Judgment of Divorce, drafting additional orders that might be needs (such as a QDRO and/or USSO) are all good reasons that lawyers have years of training. Most people don't consider doing surgery on themselves but for some reason seem to believe they're qualified to practice law on themselves. I've never figured out that crazy line of thinking.