Hi Horty
You should get a review form 6 months before your PIP claim stops, if you do not receive a review form then contact DWP and ask for one.
If you are in receipt of PIP before you reach state pension age then your claim will continue after you reach state pension age.
If you are in receipt of PIP, you cannot claim Attendance Allowance, remember Attendance Allowance is all about care needs, there is no mobility component with Attendance Allowance.
Gary
Nothing on this board constitutes legal advice - always consult a professional about specific problems