I'm sorry that I can't answer most of your questions, but I can definitely say get the booster done as soon as possible!
My DH & I were discussing getting the booster done for him and the kids before the baby gets here... and about 2-3 weeks after discussing it me & the kids contracted whooping cough. I can tell you now it is the WORST thing I have been through. My poor kids are only just getting over it. I am still phlegmy and have a cough at night and I was diagnosed with WC close to 3 weeks ago and suffered through it for a week before diagnosis. My youngest son (2) is fully immunised against WC but he still got it. It has been awful seeing him cough until he basically can't breathe and he has been vomitting phlegm after some coughing fits I would hate to see a newborn suffer through this illness.