1. There is no problem in transferring the Children’s Tax Credit to your husband so that he has it in his tax code. Simply write to your tax office, making sure that you include both of your National Insurance Numbers, explaining that you now wish him to have the full CTC.
2. Yes, when your tax code is changed to accommodate the Children’s Tax Credit, you should get your tax refund in your next pay period, assuming you are on PAYE.