Planning to some renovation work after staying 10 years..hopefully some sifu can give estimated price for the work

1.Make gate wider by demolishing mailbox - Do I need to buy new gate or there is way to modified it?
2.Relocate from side door to middle door so need to rebuild 2 Windows + security door.
3.Build 2 pillar to support balcony
4.Build roof+extension for 2nd floor room - Previous contractor claim existing kitchen extension can support 2nd floor extension.
5.Re-paint whole house
6.Demolish 2 walls