So lets hope that in release they have the appropriate techs as well as maintaining their factories. Perhaps also add a CSA event to raise an immediate army. Lets also not forget that from the time of succession to the First Battle of Bull Run, it was three months. Perhaps some additional events such as a paralysis on the Union armies (their offers leaving under gentlemanly agreement) for a month or so as well as new states have to have free vs slave state decided by popular vote during their joining of the US.
Wouldn't work. For one thing you can't just have an army appear, you'd need to convert some Dixie pops to soldiers and attach them to that, And freezing all the union troops would be bad, imagine if the US happened to be at war with another nation too.
A possible idea might be to convert a percentage of Dixie farmers/labours to Soldiers every time a free state is added to the US so the south can raise more troops, but the player could be gamey if he wanted, recruit those troops and send them somewhere remote/deadly. I don't know, have them all teleport to their home provinces when the CSA forms?