You can take 6=12 clones from bottom of plant. Usually it is best to take a branch and get all the cuttings from that. Best not to take more than 2 branches in a week to twos time.

You can flower the mom afterward, but I would make sure the cuttings rooted before I flower her.

No. the branches will not grow back.

Look in Growfaqs for cloning faq. It will tell you exactly what to do.