Questions regarding Great Wall Visit

HI there

Would appreciate it if anyone answer the following questions:
1. After getting the cable-car up, is it possible to walk from North Section Tower 8 to South Section Tower 4 using just the 1 admittance ticket, or would I need to buy 2?
2. The approximate time this walk would take?
3. Visiting on a Monday (near the end of September), would it be better to visit early morning (09:00) or late afternoon (15:00)?

Many thanks