1 = National Express coach
2 = National Express coach or Uber/pre booked taxi. Not a lot of difference
3 = Uber/pre booked taxi.
7 = Contact a limo/minibus service. May get 1 vehicle. but may depend on your baggage.

Are several threads on LHR<--->LGW transfers. A common question.
https://www.flyertalk.com/forum/u-k-ireland-484/
LHR <--> LGW connection, MCT, transport, etc. (merged threads)
The Ongoing LHR Taxi/Minicab (Car Service) Discussion
London Airports transfer FAQ: London Heathrow (LHR)
UK & Ireland Dashboard: London Airport Transfers, Rail, Eurostar & Destination Guides

Edit
OP posted in another (more up to date) thread
https://www.flyertalk.com/forum/brit...l-guide-6.html